diff --git a/src/debuginfo.cpp b/src/debuginfo.cpp
index 737508301776a..c092bbf458a93 100644
--- a/src/debuginfo.cpp
+++ b/src/debuginfo.cpp
@@ -1087,7 +1087,8 @@ static int jl_getDylibFunctionInfo(jl_frame_t **frames, size_t pointer, int skip
         for (size_t i = 0; i < sysimg_fptrs.nclones; i++) {
             if (diff == sysimg_fptrs.clone_offsets[i]) {
                 uint32_t idx = sysimg_fptrs.clone_idxs[i] & jl_sysimg_val_mask;
-                frame0->linfo = sysimg_fvars_linfo[idx];
+                if (idx < sysimg_fvars_n) // items after this were cloned but not referenced directly by a method (such as our ccall PLT thunks)
+                    frame0->linfo = sysimg_fvars_linfo[idx];
                 break;
             }
         }
diff --git a/src/staticdata.c b/src/staticdata.c
index 921abb4b770be..363e0d716c3bb 100644
--- a/src/staticdata.c
+++ b/src/staticdata.c
@@ -1016,6 +1016,7 @@ static void jl_update_all_fptrs(jl_serializer_state *s)
     for (i = 0; i < sysimg_fvars_max; i++) {
         uintptr_t val = (uintptr_t)&linfos[i];
         uint32_t offset = load_uint32(&val);
+        linfos[i] = NULL;
         if (offset != 0) {
             int specfunc = 1;
             if (offset & ((uintptr_t)1 << (8 * sizeof(uint32_t) - 1))) {
diff --git a/stdlib/Profile/src/Profile.jl b/stdlib/Profile/src/Profile.jl
index 5cb34e132942f..8ae9542c2c2f4 100644
--- a/stdlib/Profile/src/Profile.jl
+++ b/stdlib/Profile/src/Profile.jl
@@ -514,6 +514,7 @@ function tree!(root::StackFrameTree{T}, all::Vector{UInt64}, lidict::Union{LineI
                 # jump forward to the end of the inlining chain
                 # avoiding an extra (slow) lookup of `ip` in `lidict`
                 # and an extra chain of them in `down`
+                # note that we may even have this === parent (if we're ignoring this frame ip)
                 this = builder_value[fastkey]
                 let this = this
                     while this !== parent
@@ -532,8 +533,7 @@ function tree!(root::StackFrameTree{T}, all::Vector{UInt64}, lidict::Union{LineI
                 frame = (frames isa Vector ? frames[i] : frames)
                 !C && frame.from_c && continue
                 key = (T === UInt64 ? ip : frame)
-                down = parent.down
-                this = get!(down, key) do
+                this = get!(parent.down, key) do
                     return StackFrameTree{T}()
                 end
                 this.frame = frame