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Xen balloon: make API for inc/dec page reservation #18

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andr2000 opened this issue Jul 27, 2017 · 0 comments
Open

Xen balloon: make API for inc/dec page reservation #18

andr2000 opened this issue Jul 27, 2017 · 0 comments
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@andr2000
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Currently there is no API for page reservation inc/dec and we have to copy code for this from the Xen balloon driver into DRM z-copy driver. It was discussed with Andrew Cooper that it can be a good idea to remove that code duplication by extending API of the Xen balloon driver instead

@andr2000 andr2000 self-assigned this Jul 27, 2017
andr2000 pushed a commit to andr2000/linux that referenced this issue Mar 13, 2018
when sock_create_kern(..., a) returns an error, 'a' might not be a valid
pointer, so it shouldn't be dereferenced to read a->sk->sk_sndbuf and
and a->sk->sk_rcvbuf; not doing that caused the following crash:

general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4254 Comm: syzkaller919713 Not tainted 4.16.0-rc1+ xen-troops#18
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:smc_create+0x14e/0x300 net/smc/af_smc.c:1410
RSP: 0018:ffff8801b06afbc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801b63457c0 RCX: ffffffff85a3e746
RDX: 0000000000000004 RSI: 00000000ffffffff RDI: 0000000000000020
RBP: ffff8801b06afbf0 R08: 00000000000007c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8801b6345c08 R14: 00000000ffffffe9 R15: ffffffff8695ced0
FS:  0000000001afb880(0000) GS:ffff8801db200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000040 CR3: 00000001b0721004 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  __sock_create+0x4d4/0x850 net/socket.c:1285
  sock_create net/socket.c:1325 [inline]
  SYSC_socketpair net/socket.c:1409 [inline]
  SyS_socketpair+0x1c0/0x6f0 net/socket.c:1366
  do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x26/0x9b
RIP: 0033:0x4404b9
RSP: 002b:00007fff44ab6908 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004404b9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000002b
RBP: 00007fff44ab6910 R08: 0000000000000002 R09: 00007fff44003031
R10: 0000000020000040 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000
Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 01 00 00 4c 8b a3 48 04 00 00 48
b8
00 00 00 00 00 fc ff df 49 8d 7c 24 20 48 89 fa 48 c1 ea 03 <80> 3c 02
00
0f 85 82 01 00 00 4d 8b 7c 24 20 48 b8 00 00 00 00
RIP: smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: ffff8801b06afbc8

Fixes: cd6851f smc: remote memory buffers (RMBs)
Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
andr2000 pushed a commit to andr2000/linux that referenced this issue Mar 13, 2018
dev_get_by_index is being called in addr_resolve
function which returns NULL and NULL pointer access
leads to kernel crash.

Following call trace is observed while running
rdma_lat test application

[  146.173149] BUG: unable to handle kernel NULL pointer dereference
at 00000000000004a0
[  146.173198] IP: addr_resolve+0x9e/0x3e0 [ib_core]
[  146.173221] PGD 0 P4D 0
[  146.173869] Oops: 0000 [#1] SMP PTI
[  146.182859] CPU: 8 PID: 127 Comm: kworker/8:1 Tainted: G  O 4.15.0-rc6+ xen-troops#18
[  146.183758] Hardware name: LENOVO System x3650 M5: -[8871AC1]-/01KN179,
 BIOS-[TCE132H-2.50]- 10/11/2017
[  146.184691] Workqueue: ib_cm cm_work_handler [ib_cm]
[  146.185632] RIP: 0010:addr_resolve+0x9e/0x3e0 [ib_core]
[  146.186584] RSP: 0018:ffffc9000362faa0 EFLAGS: 00010246
[  146.187521] RAX: 000000000000001b RBX: ffffc9000362fc08 RCX:
0000000000000006
[  146.188472] RDX: 0000000000000000 RSI: 0000000000000096 RDI
: ffff88087fc16990
[  146.189427] RBP: ffffc9000362fb18 R08: 00000000ffffff9d R09:
00000000000004ac
[  146.190392] R10: 00000000000001e7 R11: 0000000000000001 R12:
ffff88086af2e090
[  146.191361] R13: 0000000000000000 R14: 0000000000000001 R15:
00000000ffffff9d
[  146.192327] FS:  0000000000000000(0000) GS:ffff88087fc00000(0000)
knlGS:0000000000000000
[  146.193301] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  146.194274] CR2: 00000000000004a0 CR3: 000000000220a002 CR4:
00000000003606e0
[  146.195258] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  146.196256] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[  146.197231] Call Trace:
[  146.198209]  ? rdma_addr_register_client+0x30/0x30 [ib_core]
[  146.199199]  rdma_resolve_ip+0x1af/0x280 [ib_core]
[  146.200196]  rdma_addr_find_l2_eth_by_grh+0x154/0x2b0 [ib_core]

The below patch adds the missing NULL pointer check
returned by dev_get_by_index before accessing the netdev to
avoid kernel crash.

We observed the below crash when we try to do the below test.

 server                       client
 ---------                    ---------
 |1.1.1.1|<----rxe-channel--->|1.1.1.2|
 ---------                    ---------

On server: rdma_lat -c -n 2 -s 1024
On client:rdma_lat 1.1.1.1 -c -n 2 -s 1024

Fixes: 2002983 ("IB/core: Validate route when we init ah")
Signed-off-by: Muneendra <muneendra.kumar@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
andr2000 pushed a commit to andr2000/linux that referenced this issue May 23, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 xen-troops#32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 xen-troops#47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 xen-troops#47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ xen-troops#26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
andr2000 pushed a commit to andr2000/linux that referenced this issue May 23, 2018
Currently only nvme_ctrl will take a reference counter of
nvme_subsystem, nvme_ns_head also needs it. Otherwise
nvme_free_ns_head will access the nvme_subsystem.ns_ida
which has been freed by __nvme_release_subsystem after all the
reference of nvme_subsystem have been released by nvme_free_ctrl.
This could cause memory corruption.

 BUG: KASAN: use-after-free in radix_tree_next_chunk+0x9f/0x4b0
 Read of size 8 at addr ffff88036494d2e8 by task fio/1815

 CPU: 1 PID: 1815 Comm: fio Kdump: loaded Tainted: G        W         4.17.0-rc1+ xen-troops#18
 Hardware name: LENOVO 10MLS0E339/3106, BIOS M1AKT22A 06/27/2017
 Call Trace:
  dump_stack+0x91/0xeb
  print_address_description+0x6b/0x290
  kasan_report+0x261/0x360
  radix_tree_next_chunk+0x9f/0x4b0
  ida_remove+0x8b/0x180
  ida_simple_remove+0x26/0x40
  nvme_free_ns_head+0x58/0xc0
  __blkdev_put+0x30a/0x3a0
  blkdev_close+0x44/0x50
  __fput+0x184/0x380
  task_work_run+0xaf/0xe0
  do_exit+0x501/0x1440
  do_group_exit+0x89/0x140
  __x64_sys_exit_group+0x28/0x30
  do_syscall_64+0x72/0x230

Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
andr2000 pushed a commit to andr2000/linux that referenced this issue Sep 19, 2018
The following lockdep report can be triggered by writing to /sys/kernel/debug/sched_features:

  ======================================================
  WARNING: possible circular locking dependency detected
  4.18.0-rc6-00152-gcd3f77d74ac3-dirty xen-troops#18 Not tainted
  ------------------------------------------------------
  sh/3358 is trying to acquire lock:
  000000004ad3989d (cpu_hotplug_lock.rw_sem){++++}, at: static_key_enable+0x14/0x30
  but task is already holding lock:
  00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  which lock already depends on the new lock.
  the existing dependency chain (in reverse order) is:
  -> #3 (&sb->s_type->i_mutex_key#3){+.+.}:
         lock_acquire+0xb8/0x148
         down_write+0xac/0x140
         start_creating+0x5c/0x168
         debugfs_create_dir+0x18/0x220
         opp_debug_register+0x8c/0x120
         _add_opp_dev+0x104/0x1f8
         dev_pm_opp_get_opp_table+0x174/0x340
         _of_add_opp_table_v2+0x110/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> #2 (opp_table_lock){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         _of_add_opp_table_v2+0xb4/0x760
         dev_pm_opp_of_add_table+0x5c/0x240
         dev_pm_opp_of_cpumask_add_table+0x5c/0x100
         cpufreq_init+0x160/0x430
         cpufreq_online+0x1cc/0xe30
         cpufreq_add_dev+0x78/0x198
         subsys_interface_register+0x168/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> #1 (subsys mutex#6){+.+.}:
         lock_acquire+0xb8/0x148
         __mutex_lock+0x104/0xf50
         mutex_lock_nested+0x1c/0x28
         subsys_interface_register+0xd8/0x270
         cpufreq_register_driver+0x1c8/0x278
         dt_cpufreq_probe+0xdc/0x1b8
         platform_drv_probe+0xb4/0x168
         driver_probe_device+0x318/0x4b0
         __device_attach_driver+0xfc/0x1f0
         bus_for_each_drv+0xf8/0x180
         __device_attach+0x164/0x200
         device_initial_probe+0x10/0x18
         bus_probe_device+0x110/0x178
         device_add+0x6d8/0x908
         platform_device_add+0x138/0x3d8
         platform_device_register_full+0x1cc/0x1f8
         cpufreq_dt_platdev_init+0x174/0x1bc
         do_one_initcall+0xb8/0x310
         kernel_init_freeable+0x4b8/0x56c
         kernel_init+0x10/0x138
         ret_from_fork+0x10/0x18
  -> #0 (cpu_hotplug_lock.rw_sem){++++}:
         __lock_acquire+0x203c/0x21d0
         lock_acquire+0xb8/0x148
         cpus_read_lock+0x58/0x1c8
         static_key_enable+0x14/0x30
         sched_feat_write+0x314/0x428
         full_proxy_write+0xa0/0x138
         __vfs_write+0xd8/0x388
         vfs_write+0xdc/0x318
         ksys_write+0xb4/0x138
         sys_write+0xc/0x18
         __sys_trace_return+0x0/0x4
  other info that might help us debug this:
  Chain exists of:
    cpu_hotplug_lock.rw_sem --> opp_table_lock --> &sb->s_type->i_mutex_key#3
   Possible unsafe locking scenario:
         CPU0                    CPU1
         ----                    ----
    lock(&sb->s_type->i_mutex_key#3);
                                 lock(opp_table_lock);
                                 lock(&sb->s_type->i_mutex_key#3);
    lock(cpu_hotplug_lock.rw_sem);
   *** DEADLOCK ***
  2 locks held by sh/3358:
   #0: 00000000a8c4b363 (sb_writers#10){.+.+}, at: vfs_write+0x238/0x318
   #1: 00000000c1b31a88 (&sb->s_type->i_mutex_key#3){+.+.}, at: sched_feat_write+0x160/0x428
  stack backtrace:
  CPU: 5 PID: 3358 Comm: sh Not tainted 4.18.0-rc6-00152-gcd3f77d74ac3-dirty xen-troops#18
  Hardware name: Renesas H3ULCB Kingfisher board based on r8a7795 ES2.0+ (DT)
  Call trace:
   dump_backtrace+0x0/0x288
   show_stack+0x14/0x20
   dump_stack+0x13c/0x1ac
   print_circular_bug.isra.10+0x270/0x438
   check_prev_add.constprop.16+0x4dc/0xb98
   __lock_acquire+0x203c/0x21d0
   lock_acquire+0xb8/0x148
   cpus_read_lock+0x58/0x1c8
   static_key_enable+0x14/0x30
   sched_feat_write+0x314/0x428
   full_proxy_write+0xa0/0x138
   __vfs_write+0xd8/0x388
   vfs_write+0xdc/0x318
   ksys_write+0xb4/0x138
   sys_write+0xc/0x18
   __sys_trace_return+0x0/0x4

This is because when loading the cpufreq_dt module we first acquire
cpu_hotplug_lock.rw_sem lock, then in cpufreq_init(), we are taking
the &sb->s_type->i_mutex_key lock.

But when writing to /sys/kernel/debug/sched_features, the
cpu_hotplug_lock.rw_sem lock depends on the &sb->s_type->i_mutex_key lock.

To fix this bug, reverse the lock acquisition order when writing to
sched_features, this way cpu_hotplug_lock.rw_sem no longer depends on
&sb->s_type->i_mutex_key.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: George G. Davis <george_davis@mentor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180731121222.26195-1-jiada_wang@mentor.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
andr2000 pushed a commit to andr2000/linux that referenced this issue Nov 27, 2018
Increase kasan instrumented kernel stack size from 32k to 64k. Other
architectures seems to get away with just doubling kernel stack size under
kasan, but on s390 this appears to be not enough due to bigger frame size.
The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE
vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting
stack overflow is fs sync on xfs filesystem:

 #0 [9a0681e8]  704 bytes  check_usage at 34b1fc
 #1 [9a0684a8]  432 bytes  check_usage at 34c710
 #2 [9a068658]  1048 bytes  validate_chain at 35044a
 #3 [9a068a70]  312 bytes  __lock_acquire at 3559fe
 xen-troops#4 [9a068ba8]  440 bytes  lock_acquire at 3576ee
 xen-troops#5 [9a068d60]  104 bytes  _raw_spin_lock at 21b44e0
 xen-troops#6 [9a068dc8]  1992 bytes  enqueue_entity at 2dbf72
 xen-troops#7 [9a069590]  1496 bytes  enqueue_task_fair at 2df5f0
 xen-troops#8 [9a069b68]  64 bytes  ttwu_do_activate at 28f438
 xen-troops#9 [9a069ba8]  552 bytes  try_to_wake_up at 298c4c
 xen-troops#10 [9a069dd0]  168 bytes  wake_up_worker at 23f97c
 xen-troops#11 [9a069e78]  200 bytes  insert_work at 23fc2e
 xen-troops#12 [9a069f40]  648 bytes  __queue_work at 2487c0
 xen-troops#13 [9a06a1c8]  200 bytes  __queue_delayed_work at 24db28
 xen-troops#14 [9a06a290]  248 bytes  mod_delayed_work_on at 24de84
 xen-troops#15 [9a06a388]  24 bytes  kblockd_mod_delayed_work_on at 153e2a0
 xen-troops#16 [9a06a3a0]  288 bytes  __blk_mq_delay_run_hw_queue at 158168c
 xen-troops#17 [9a06a4c0]  192 bytes  blk_mq_run_hw_queue at 1581a3c
 xen-troops#18 [9a06a580]  184 bytes  blk_mq_sched_insert_requests at 15a2192
 xen-troops#19 [9a06a638]  1024 bytes  blk_mq_flush_plug_list at 1590f3a
 xen-troops#20 [9a06aa38]  704 bytes  blk_flush_plug_list at 1555028
 xen-troops#21 [9a06acf8]  320 bytes  schedule at 219e476
 xen-troops#22 [9a06ae38]  760 bytes  schedule_timeout at 21b0aac
 xen-troops#23 [9a06b130]  408 bytes  wait_for_common at 21a1706
 xen-troops#24 [9a06b2c8]  360 bytes  xfs_buf_iowait at fa1540
 xen-troops#25 [9a06b430]  256 bytes  __xfs_buf_submit at fadae6
 xen-troops#26 [9a06b530]  264 bytes  xfs_buf_read_map at fae3f6
 xen-troops#27 [9a06b638]  656 bytes  xfs_trans_read_buf_map at 10ac9a8
 xen-troops#28 [9a06b8c8]  304 bytes  xfs_btree_kill_root at e72426
 xen-troops#29 [9a06b9f8]  288 bytes  xfs_btree_lookup_get_block at e7bc5e
 xen-troops#30 [9a06bb18]  624 bytes  xfs_btree_lookup at e7e1a6
 xen-troops#31 [9a06bd88]  2664 bytes  xfs_alloc_ag_vextent_near at dfa070
 xen-troops#32 [9a06c7f0]  144 bytes  xfs_alloc_ag_vextent at dff3ca
 xen-troops#33 [9a06c880]  1128 bytes  xfs_alloc_vextent at e05fce
 xen-troops#34 [9a06cce8]  584 bytes  xfs_bmap_btalloc at e58342
 xen-troops#35 [9a06cf30]  1336 bytes  xfs_bmapi_write at e618de
 xen-troops#36 [9a06d468]  776 bytes  xfs_iomap_write_allocate at ff678e
 xen-troops#37 [9a06d770]  720 bytes  xfs_map_blocks at f82af8
 xen-troops#38 [9a06da40]  928 bytes  xfs_writepage_map at f83cd6
 xen-troops#39 [9a06dde0]  320 bytes  xfs_do_writepage at f85872
 xen-troops#40 [9a06df20]  1320 bytes  write_cache_pages at 73dfe8
 xen-troops#41 [9a06e448]  208 bytes  xfs_vm_writepages at f7f892
 xen-troops#42 [9a06e518]  88 bytes  do_writepages at 73fe6a
 xen-troops#43 [9a06e570]  872 bytes  __writeback_single_inode at a20cb6
 xen-troops#44 [9a06e8d8]  664 bytes  writeback_sb_inodes at a23be2
 xen-troops#45 [9a06eb70]  296 bytes  __writeback_inodes_wb at a242e0
 xen-troops#46 [9a06ec98]  928 bytes  wb_writeback at a2500e
 xen-troops#47 [9a06f038]  848 bytes  wb_do_writeback at a260ae
 xen-troops#48 [9a06f388]  536 bytes  wb_workfn at a28228
 xen-troops#49 [9a06f5a0]  1088 bytes  process_one_work at 24a234
 xen-troops#50 [9a06f9e0]  1120 bytes  worker_thread at 24ba26
 xen-troops#51 [9a06fe40]  104 bytes  kthread at 26545a
 xen-troops#52 [9a06fea8]             kernel_thread_starter at 21b6b62

To be able to increase the stack size to 64k reuse LLILL instruction
in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE
(65192) value as unsigned.

Reported-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
andr2000 pushed a commit to andr2000/linux that referenced this issue Apr 4, 2019
…mory

When halting a guest, QEMU flushes the virtual ITS caches, which
amounts to writing to the various tables that the guest has allocated.

When doing this, we fail to take the srcu lock, and the kernel
shouts loudly if running a lockdep kernel:

[   69.680416] =============================
[   69.680819] WARNING: suspicious RCU usage
[   69.681526] 5.1.0-rc1-00008-g600025238f51-dirty xen-troops#18 Not tainted
[   69.682096] -----------------------------
[   69.682501] ./include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
[   69.683225]
[   69.683225] other info that might help us debug this:
[   69.683225]
[   69.683975]
[   69.683975] rcu_scheduler_active = 2, debug_locks = 1
[   69.684598] 6 locks held by qemu-system-aar/4097:
[   69.685059]  #0: 0000000034196013 (&kvm->lock){+.+.}, at: vgic_its_set_attr+0x244/0x3a0
[   69.686087]  #1: 00000000f2ed935e (&its->its_lock){+.+.}, at: vgic_its_set_attr+0x250/0x3a0
[   69.686919]  #2: 000000005e71ea54 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.687698]  #3: 00000000c17e548d (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.688475]  xen-troops#4: 00000000ba386017 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.689978]  xen-troops#5: 00000000c2c3c335 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.690729]
[   69.690729] stack backtrace:
[   69.691151] CPU: 2 PID: 4097 Comm: qemu-system-aar Not tainted 5.1.0-rc1-00008-g600025238f51-dirty xen-troops#18
[   69.691984] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[   69.692831] Call trace:
[   69.694072]  lockdep_rcu_suspicious+0xcc/0x110
[   69.694490]  gfn_to_memslot+0x174/0x190
[   69.694853]  kvm_write_guest+0x50/0xb0
[   69.695209]  vgic_its_save_tables_v0+0x248/0x330
[   69.695639]  vgic_its_set_attr+0x298/0x3a0
[   69.696024]  kvm_device_ioctl_attr+0x9c/0xd8
[   69.696424]  kvm_device_ioctl+0x8c/0xf8
[   69.696788]  do_vfs_ioctl+0xc8/0x960
[   69.697128]  ksys_ioctl+0x8c/0xa0
[   69.697445]  __arm64_sys_ioctl+0x28/0x38
[   69.697817]  el0_svc_common+0xd8/0x138
[   69.698173]  el0_svc_handler+0x38/0x78
[   69.698528]  el0_svc+0x8/0xc

The fix is to obviously take the srcu lock, just like we do on the
read side of things since bf30824. One wonders why this wasn't
fixed at the same time, but hey...

Fixes: bf30824 ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
andr2000 pushed a commit to andr2000/linux that referenced this issue Apr 4, 2019
…r-free issue

The evlist should be destroyed before the perf session.

Detected with gcc's ASan:

  =================================================================
  ==27350==ERROR: AddressSanitizer: heap-use-after-free on address 0x62b000002e38 at pc 0x5611da276999 bp 0x7ffce8f1d1a0 sp 0x7ffce8f1d190
  WRITE of size 8 at 0x62b000002e38 thread T0
      #0 0x5611da276998 in __list_del /home/work/linux/tools/include/linux/list.h:89
      #1 0x5611da276d4a in __list_del_entry /home/work/linux/tools/include/linux/list.h:102
      #2 0x5611da276e77 in list_del_init /home/work/linux/tools/include/linux/list.h:145
      #3 0x5611da2781cd in thread__put util/thread.c:130
      xen-troops#4 0x5611da2cc0a8 in __thread__zput util/thread.h:68
      xen-troops#5 0x5611da2d2dcb in hist_entry__delete util/hist.c:1148
      xen-troops#6 0x5611da2cdf91 in hists__delete_entry util/hist.c:337
      xen-troops#7 0x5611da2ce19e in hists__delete_entries util/hist.c:365
      xen-troops#8 0x5611da2db2ab in hists__delete_all_entries util/hist.c:2639
      xen-troops#9 0x5611da2db325 in hists_evsel__exit util/hist.c:2651
      xen-troops#10 0x5611da1c5352 in perf_evsel__exit util/evsel.c:1304
      xen-troops#11 0x5611da1c5390 in perf_evsel__delete util/evsel.c:1309
      xen-troops#12 0x5611da1b35f0 in perf_evlist__purge util/evlist.c:124
      xen-troops#13 0x5611da1b38e2 in perf_evlist__delete util/evlist.c:148
      xen-troops#14 0x5611da069781 in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1645
      xen-troops#15 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      xen-troops#16 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      xen-troops#17 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      xen-troops#18 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      xen-troops#19 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
      xen-troops#20 0x5611d9ff35c9 in _start (/home/work/linux/tools/perf/perf+0x3e95c9)

  0x62b000002e38 is located 11320 bytes inside of 27448-byte region [0x62b000000200,0x62b000006d38)
  freed by thread T0 here:
      #0 0x7fdccb04ab70 in free (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedb70)
      #1 0x5611da260df4 in perf_session__delete util/session.c:201
      #2 0x5611da063de5 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1300
      #3 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      xen-troops#4 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      xen-troops#5 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      xen-troops#6 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      xen-troops#7 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      xen-troops#8 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  previously allocated by thread T0 here:
      #0 0x7fdccb04b138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5611da26010c in zalloc util/util.h:23
      #2 0x5611da260824 in perf_session__new util/session.c:118
      #3 0x5611da0633a6 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1192
      xen-troops#4 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      xen-troops#5 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      xen-troops#6 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      xen-troops#7 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      xen-troops#8 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      xen-troops#9 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  SUMMARY: AddressSanitizer: heap-use-after-free /home/work/linux/tools/include/linux/list.h:89 in __list_del
  Shadow bytes around the buggy address:
    0x0c567fff8570: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8580: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8590: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85a0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85b0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  =>0x0c567fff85c0: fd fd fd fd fd fd fd[fd]fd fd fd fd fd fd fd fd
    0x0c567fff85d0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85e0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85f0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8610: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:       fa
    Freed heap region:       fd
    Stack left redzone:      f1
    Stack mid redzone:       f2
    Stack right redzone:     f3
    Stack after return:      f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:       f6
    Poisoned by user:        f7
    Container overflow:      fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
  ==27350==ABORTING

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190316080556.3075-8-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
andr2000 pushed a commit to andr2000/linux that referenced this issue Aug 13, 2020
I compiled with AddressSanitizer and I had these memory leaks while I
was using the tep_parse_format function:

    Direct leak of 28 byte(s) in 4 object(s) allocated from:
        #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe)
        #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985
        #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140
        #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206
        xen-troops#4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
        xen-troops#5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
        xen-troops#6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
        xen-troops#7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
        xen-troops#8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
        xen-troops#9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
        xen-troops#10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
        xen-troops#11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
        xen-troops#12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
        xen-troops#13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
        xen-troops#14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
        xen-troops#15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
        xen-troops#16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
        xen-troops#17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
        xen-troops#18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
        xen-troops#19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
        xen-troops#20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
        xen-troops#21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
        xen-troops#22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
        xen-troops#23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
        xen-troops#24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
        xen-troops#25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
        xen-troops#26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

The token variable in the process_dynamic_array_len function is
allocated in the read_expect_type function, but is not freed before
calling the read_token function.

Free the token variable before calling read_token in order to plug the
leak.

Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
arminn pushed a commit to arminn/linux that referenced this issue Aug 9, 2021
…flow join

[ Upstream commit 0c71929 ]

I did stress test with wrk[1] and webfsd[2] with the assistance of
mptcp-tools[3]:

  Server side:
      ./use_mptcp.sh webfsd -4 -R /tmp/ -p 8099
  Client side:
      ./use_mptcp.sh wrk -c 200 -d 30 -t 4 http://192.168.174.129:8099/

and got the following warning message:

[   55.552626] TCP: request_sock_subflow: Possible SYN flooding on port 8099. Sending cookies.  Check SNMP counters.
[   55.553024] ------------[ cut here ]------------
[   55.553027] WARNING: CPU: 0 PID: 10 at net/core/flow_dissector.c:984 __skb_flow_dissect+0x280/0x1650
...
[   55.553117] CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.12.0+ xen-troops#18
[   55.553121] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
[   55.553124] RIP: 0010:__skb_flow_dissect+0x280/0x1650
...
[   55.553133] RSP: 0018:ffffb79580087770 EFLAGS: 00010246
[   55.553137] RAX: 0000000000000000 RBX: ffffffff8ddb58e0 RCX: ffffb79580087888
[   55.553139] RDX: ffffffff8ddb58e0 RSI: ffff8f7e4652b600 RDI: 0000000000000000
[   55.553141] RBP: ffffb79580087858 R08: 0000000000000000 R09: 0000000000000008
[   55.553143] R10: 000000008c622965 R11: 00000000d3313a5b R12: ffff8f7e4652b600
[   55.553146] R13: ffff8f7e465c9062 R14: 0000000000000000 R15: ffffb79580087888
[   55.553149] FS:  0000000000000000(0000) GS:ffff8f7f75e00000(0000) knlGS:0000000000000000
[   55.553152] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   55.553154] CR2: 00007f73d1d19000 CR3: 0000000135e10004 CR4: 00000000003706f0
[   55.553160] Call Trace:
[   55.553166]  ? __sha256_final+0x67/0xd0
[   55.553173]  ? sha256+0x7e/0xa0
[   55.553177]  __skb_get_hash+0x57/0x210
[   55.553182]  subflow_init_req_cookie_join_save+0xac/0xc0
[   55.553189]  subflow_check_req+0x474/0x550
[   55.553195]  ? ip_route_output_key_hash+0x67/0x90
[   55.553200]  ? xfrm_lookup_route+0x1d/0xa0
[   55.553207]  subflow_v4_route_req+0x8e/0xd0
[   55.553212]  tcp_conn_request+0x31e/0xab0
[   55.553218]  ? selinux_socket_sock_rcv_skb+0x116/0x210
[   55.553224]  ? tcp_rcv_state_process+0x179/0x6d0
[   55.553229]  tcp_rcv_state_process+0x179/0x6d0
[   55.553235]  tcp_v4_do_rcv+0xaf/0x220
[   55.553239]  tcp_v4_rcv+0xce4/0xd80
[   55.553243]  ? ip_route_input_rcu+0x246/0x260
[   55.553248]  ip_protocol_deliver_rcu+0x35/0x1b0
[   55.553253]  ip_local_deliver_finish+0x44/0x50
[   55.553258]  ip_local_deliver+0x6c/0x110
[   55.553262]  ? ip_rcv_finish_core.isra.19+0x5a/0x400
[   55.553267]  ip_rcv+0xd1/0xe0
...

After debugging, I found in __skb_flow_dissect(), skb->dev and skb->sk
are both NULL, then net is NULL, and trigger WARN_ON_ONCE(!net),
actually net is always NULL in this code path, as skb->dev is set to
NULL in tcp_v4_rcv(), and skb->sk is never set.

Code snippet in __skb_flow_dissect() that trigger warning:
  975         if (skb) {
  976                 if (!net) {
  977                         if (skb->dev)
  978                                 net = dev_net(skb->dev);
  979                         else if (skb->sk)
  980                                 net = sock_net(skb->sk);
  981                 }
  982         }
  983
  984         WARN_ON_ONCE(!net);

So, using seq and transport header derived hash.

[1] https://github.com/wg/wrk
[2] https://github.com/ourway/webfsd
[3] https://github.com/pabeni/mptcp-tools

Fixes: 9466a1c ("mptcp: enable JOIN requests even if cookies are in use")
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
otyshchenko1 pushed a commit to otyshchenko1/linux that referenced this issue Nov 22, 2021
Use __release_guc_id (lock held) rather than release_guc_id (acquires
lock), add lockdep annotations.

213.280129] i915: Running i915_perf_live_selftests/live_noa_gpr
[ 213.283459] ============================================
[ 213.283462] WARNING: possible recursive locking detected
{{[ 213.283466] 5.15.0-rc6+ xen-troops#18 Tainted: G U W }}
[ 213.283470] --------------------------------------------
[ 213.283472] kworker/u24:0/8 is trying to acquire lock:
[ 213.283475] ffff8ffc4f6cc1e8 (&guc->submission_state.lock){....}-{2:2}, at: destroyed_worker_func+0x2df/0x350 [i915]
{{[ 213.283618] }}
{{ but task is already holding lock:}}
[ 213.283621] ffff8ffc4f6cc1e8 (&guc->submission_state.lock){....}-{2:2}, at: destroyed_worker_func+0x4f/0x350 [i915]
{{[ 213.283720] }}
{{ other info that might help us debug this:}}
[ 213.283724] Possible unsafe locking scenario:[ 213.283727] CPU0
[ 213.283728] ----
[ 213.283730] lock(&guc->submission_state.lock);
[ 213.283734] lock(&guc->submission_state.lock);
{{[ 213.283737] }}
{{ *** DEADLOCK ***}}[ 213.283740] May be due to missing lock nesting notation[ 213.283744] 3 locks held by kworker/u24:0/8:
[ 213.283747] #0: ffff8ffb80059d38 ((wq_completion)events_unbound){..}-{0:0}, at: process_one_work+0x1f3/0x550
[ 213.283757] #1: ffffb509000e3e78 ((work_completion)(&guc->submission_state.destroyed_worker)){..}-{0:0}, at: process_one_work+0x1f3/0x550
[ 213.283766] #2: ffff8ffc4f6cc1e8 (&guc->submission_state.lock){....}-{2:2}, at: destroyed_worker_func+0x4f/0x350 [i915]
{{[ 213.283860] }}
{{ stack backtrace:}}
[ 213.283863] CPU: 8 PID: 8 Comm: kworker/u24:0 Tainted: G U W 5.15.0-rc6+ xen-troops#18
[ 213.283868] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 0403 01/26/2021
[ 213.283873] Workqueue: events_unbound destroyed_worker_func [i915]
[ 213.283957] Call Trace:
[ 213.283960] dump_stack_lvl+0x57/0x72
[ 213.283966] __lock_acquire.cold+0x191/0x2d3
[ 213.283972] lock_acquire+0xb5/0x2b0
[ 213.283978] ? destroyed_worker_func+0x2df/0x350 [i915]
[ 213.284059] ? destroyed_worker_func+0x2d7/0x350 [i915]
[ 213.284139] ? lock_release+0xb9/0x280
[ 213.284143] _raw_spin_lock_irqsave+0x48/0x60
[ 213.284148] ? destroyed_worker_func+0x2df/0x350 [i915]
[ 213.284226] destroyed_worker_func+0x2df/0x350 [i915]
[ 213.284310] process_one_work+0x270/0x550
[ 213.284315] worker_thread+0x52/0x3b0
[ 213.284319] ? process_one_work+0x550/0x550
[ 213.284322] kthread+0x135/0x160
[ 213.284326] ? set_kthread_struct+0x40/0x40
[ 213.284331] ret_from_fork+0x1f/0x30

and a bit later in the trace:

{{ 227.499864] do_raw_spin_lock+0x94/0xa0}}
[ 227.499868] _raw_spin_lock_irqsave+0x50/0x60
[ 227.499871] ? guc_flush_destroyed_contexts+0x4f/0xf0 [i915]
[ 227.499995] guc_flush_destroyed_contexts+0x4f/0xf0 [i915]
[ 227.500104] intel_guc_submission_reset_prepare+0x99/0x4b0 [i915]
[ 227.500209] ? mark_held_locks+0x49/0x70
[ 227.500212] intel_uc_reset_prepare+0x46/0x50 [i915]
[ 227.500320] reset_prepare+0x78/0x90 [i915]
[ 227.500412] __intel_gt_set_wedged.part.0+0x13/0xe0 [i915]
[ 227.500485] intel_gt_set_wedged.part.0+0x54/0x100 [i915]
[ 227.500556] intel_gt_set_wedged_on_fini+0x1a/0x30 [i915]
[ 227.500622] intel_gt_driver_unregister+0x1e/0x60 [i915]
[ 227.500694] i915_driver_remove+0x4a/0xf0 [i915]
[ 227.500767] i915_pci_probe+0x84/0x170 [i915]
[ 227.500838] local_pci_probe+0x42/0x80
[ 227.500842] pci_device_probe+0xd9/0x190
[ 227.500844] really_probe+0x1f2/0x3f0
[ 227.500847] __driver_probe_device+0xfe/0x180
[ 227.500848] driver_probe_device+0x1e/0x90
[ 227.500850] __driver_attach+0xc4/0x1d0
[ 227.500851] ? __device_attach_driver+0xe0/0xe0
[ 227.500853] ? __device_attach_driver+0xe0/0xe0
[ 227.500854] bus_for_each_dev+0x64/0x90
[ 227.500856] bus_add_driver+0x12e/0x1f0
[ 227.500857] driver_register+0x8f/0xe0
[ 227.500859] i915_init+0x1d/0x8f [i915]
[ 227.500934] ? 0xffffffffc144a000
[ 227.500936] do_one_initcall+0x58/0x2d0
[ 227.500938] ? rcu_read_lock_sched_held+0x3f/0x80
[ 227.500940] ? kmem_cache_alloc_trace+0x238/0x2d0
[ 227.500944] do_init_module+0x5c/0x270
[ 227.500946] __do_sys_finit_module+0x95/0xe0
[ 227.500949] do_syscall_64+0x38/0x90
[ 227.500951] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 227.500953] RIP: 0033:0x7ffa59d2ae0d
[ 227.500954] Code: c8 0c 00 0f 05 eb a9 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3b 80 0c 00 f7 d8 64 89 01 48
[ 227.500955] RSP: 002b:00007fff320bbf48 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 227.500956] RAX: ffffffffffffffda RBX: 00000000022ea710 RCX: 00007ffa59d2ae0d
[ 227.500957] RDX: 0000000000000000 RSI: 00000000022e1d90 RDI: 0000000000000004
[ 227.500958] RBP: 0000000000000020 R08: 00007ffa59df3a60 R09: 0000000000000070
[ 227.500958] R10: 00000000022e1d90 R11: 0000000000000246 R12: 00000000022e1d90
[ 227.500959] R13: 00000000022e58e0 R14: 0000000000000043 R15: 00000000022e42c0

v2:
 (CI build)
  - Fix build error

Fixes: 1a52fae ("drm/i915/guc: Take GT PM ref when deregistering context")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211020192147.8048-1-matthew.brost@intel.com
(cherry picked from commit 12a9917)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
otyshchenko1 pushed a commit to otyshchenko1/linux that referenced this issue Dec 9, 2021
Possible recursive locking is detected by lockdep when SMC
falls back to TCP. The corresponding warnings are as follows:

 ============================================
 WARNING: possible recursive locking detected
 5.16.0-rc1+ xen-troops#18 Tainted: G            E
 --------------------------------------------
 wrk/1391 is trying to acquire lock:
 ffff975246c8e7d8 (&ei->socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0x109/0x250 [smc]

 but task is already holding lock:
 ffff975246c8f918 (&ei->socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0xfe/0x250 [smc]

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&ei->socket.wq.wait);
   lock(&ei->socket.wq.wait);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 2 locks held by wrk/1391:
  #0: ffff975246040130 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_connect+0x43/0x150 [smc]
  #1: ffff975246c8f918 (&ei->socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0xfe/0x250 [smc]

 stack backtrace:
 Call Trace:
  <TASK>
  dump_stack_lvl+0x56/0x7b
  __lock_acquire+0x951/0x11f0
  lock_acquire+0x27a/0x320
  ? smc_switch_to_fallback+0x109/0x250 [smc]
  ? smc_switch_to_fallback+0xfe/0x250 [smc]
  _raw_spin_lock_irq+0x3b/0x80
  ? smc_switch_to_fallback+0x109/0x250 [smc]
  smc_switch_to_fallback+0x109/0x250 [smc]
  smc_connect_fallback+0xe/0x30 [smc]
  __smc_connect+0xcf/0x1090 [smc]
  ? mark_held_locks+0x61/0x80
  ? __local_bh_enable_ip+0x77/0xe0
  ? lockdep_hardirqs_on+0xbf/0x130
  ? smc_connect+0x12a/0x150 [smc]
  smc_connect+0x12a/0x150 [smc]
  __sys_connect+0x8a/0xc0
  ? syscall_enter_from_user_mode+0x20/0x70
  __x64_sys_connect+0x16/0x20
  do_syscall_64+0x34/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae

The nested locking in smc_switch_to_fallback() is considered to
possibly cause a deadlock because smc_wait->lock and clc_wait->lock
are the same type of lock. But actually it is safe so far since
there is no other place trying to obtain smc_wait->lock when
clc_wait->lock is held. So the patch replaces spin_lock() with
spin_lock_nested() to avoid false report by lockdep.

Link: https://lkml.org/lkml/2021/11/19/962
Fixes: 2153bd1 ("Transfer remaining wait queue entries during fallback")
Reported-by: syzbot+e979d3597f48262cb4ee@syzkaller.appspotmail.com
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
otyshchenko1 pushed a commit to otyshchenko1/linux that referenced this issue Mar 15, 2022
When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.

    [  755.549084] mlx5_core 0000:12:00.1: Shutdown was called
    [  756.404455] mlx5_core 0000:12:00.0: Shutdown was called
    ...
    [  757.937260] BUG: unable to handle kernel NULL pointer dereference at           (null)
    [  758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280

    crash> bt
    ...
    PID: 12649  TASK: ffff8924108f2100  CPU: 1   COMMAND: "amsd"
    ...
     xen-troops#9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
        [exception RIP: dma_pool_alloc+0x1ab]
        RIP: ffffffff8ee11acb  RSP: ffff89240e1a3968  RFLAGS: 00010046
        RAX: 0000000000000246  RBX: ffff89243d874100  RCX: 0000000000001000
        RDX: 0000000000000000  RSI: 0000000000000246  RDI: ffff89243d874090
        RBP: ffff89240e1a39c0   R8: 000000000001f080   R9: ffff8905ffc03c00
        R10: ffffffffc04680d4  R11: ffffffff8edde9fd  R12: 00000000000080d0
        R13: ffff89243d874090  R14: ffff89243d874080  R15: 0000000000000000
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    xen-troops#10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
    xen-troops#11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
    xen-troops#12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
    xen-troops#13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
    xen-troops#14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
    xen-troops#15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
    xen-troops#16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
    xen-troops#17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
    xen-troops#18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
    xen-troops#19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
    xen-troops#20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
    xen-troops#21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
    xen-troops#22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
    xen-troops#23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
    xen-troops#24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
    xen-troops#25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
    xen-troops#26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92

    crash> net_device.state ffff89443b0c0000
      state = 0x5  (__LINK_STATE_START| __LINK_STATE_NOCARRIER)

To prevent this scenario, we also make sure that the netdevice is present.

Signed-off-by: suresh kumar <suresh2514@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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