6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eduard Zingerman eddyz87@gmail.com
[ Upstream commit 42be23e8f2dcb100cb9944b2b54b6bf41aff943d ]
Fuzzer reported a memory access error in bpf_program__record_reloc() that happens when: - ".addr_space.1" section exists - there is a relocation referencing this section - there are no arena maps defined in BTF.
Sanity checks for maps existence are already present in bpf_program__record_reloc(), hence this commit adds another one.
[1] https://github.com/libbpf/libbpf/actions/runs/16375110681/job/46272998064
Signed-off-by: Eduard Zingerman eddyz87@gmail.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20250718222059.281526-1-eddyz87@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/libbpf.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 747cef47e685..e33cf3caf8b6 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4546,6 +4546,11 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
/* arena data relocation */ if (shdr_idx == obj->efile.arena_data_shndx) { + if (obj->arena_map_idx < 0) { + pr_warn("prog '%s': bad arena data relocation at insn %u, no arena maps defined\n", + prog->name, insn_idx); + return -LIBBPF_ERRNO__RELOC; + } reloc_desc->type = RELO_DATA; reloc_desc->insn_idx = insn_idx; reloc_desc->map_idx = obj->arena_map_idx;