tree 46e4bff6df3aeedda7a1324e03c434eead04d3f1
parent 24c655f17e87549264415a34d9ed8982ff3fd706
author Ihor Solodrai <ihor.solodrai@pm.me> 1736476301 +0000
committer Arnaldo Carvalho de Melo <acme@redhat.com> 1736516976 -0300

btf_encoder: Always initialize func_state to 0

BPF CI caught a segfault on aarch64 and s390x [1] after recent merges
into the master branch.

The segfault happened at free(func_state->annots) in
btf_encoder__delete_saved_funcs().

func_state->annots arrived there uninitialized because after patch [2]
in some cases func_state may be allocated with a realloc, but was not
zeroed out.

Fix this bug by always memset-ing a func_state to zero in
btf_encoder__alloc_func_state().

[1] https://github.com/kernel-patches/bpf/actions/runs/12700574327
[2] https://lore.kernel.org/dwarves/20250109185950.653110-11-ihor.solodrai@pm.me/

Tested-by: Alan Maguire <alan.maguire@oracle.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mykola Lysenko <mykolal@fb.com>
Link: https://lore.kernel.org/r/20250110023138.659519-1-ihor.solodrai@pm.me
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>