Race condition in the prepare_binprm function in fs/exec.c in the Linux kernel before 3.19.6 allows local users to gain privileges by executing a setuid program at a time instant when a chown to root is in progress, and the ownership is changed but the setuid bit is not yet stripped.

References

• https://nvd.nist.gov/vuln/detail/CVE-2015-3339
• torvalds/linux@8b01fc8
• https://bugzilla.redhat.com/show_bug.cgi?id=1214030
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=8b01fc86b9f425899f8a3a8fc1c47d73c2c20543
• http://lists.fedoraproject.org/pipermail/package-announce/2015-May/157897.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-May/158804.html
• http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00011.html
• http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00007.html
• http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00008.html
• http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00009.html
• http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00011.html
• http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00038.html
• http://rhn.redhat.com/errata/RHSA-2015-1272.html
• http://www.debian.org/security/2015/dsa-3237
• http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.19.6
• http://www.openwall.com/lists/oss-security/2015/04/20/5
• http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
• http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
• http://www.securitytracker.com/id/1032412