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| author | Shung-Hsi Yu <shung-hsi.yu@suse.com> | 2022-10-12 05:23:53 +0300 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2022-10-13 20:53:34 +0300 |
| commit | d0d382f95a9270dcf803539d6781d6bd67e3f5b2 (patch) | |
| tree | f42662b1b505ba76f5f4e635ebd6d003295c8342 | |
| parent | 35a855509e6ee3442477c8ebc6827b5b5d32a7b5 (diff) | |
| download | linux-d0d382f95a9270dcf803539d6781d6bd67e3f5b2.tar.xz | |
libbpf: Fix null-pointer dereference in find_prog_by_sec_insn()
When there are no program sections, obj->programs is left unallocated,
and find_prog_by_sec_insn()'s search lands on &obj->programs[0] == NULL,
and will cause null-pointer dereference in the following access to
prog->sec_idx.
Guard the search with obj->nr_programs similar to what's being done in
__bpf_program__iter() to prevent null-pointer access from happening.
Fixes: db2b8b06423c ("libbpf: Support CO-RE relocations for multi-prog sections")
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221012022353.7350-4-shung-hsi.yu@suse.com
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 29e9df0c232b..8c3f236c86e4 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4115,6 +4115,9 @@ static struct bpf_program *find_prog_by_sec_insn(const struct bpf_object *obj, int l = 0, r = obj->nr_programs - 1, m; struct bpf_program *prog; + if (!obj->nr_programs) + return NULL; + while (l < r) { m = l + (r - l + 1) / 2; prog = &obj->programs[m]; |