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authorMartin KaFai Lau <kafai@fb.com>2018-12-19 13:01:01 -0800
committerAlexei Starovoitov <ast@kernel.org>2018-12-19 15:42:55 -0800
commitfdbaa0beb78b7c8847e261fe2c32816e9d1c54cc (patch)
treeb99ead4b2f848949b21d9b5a0cb552b4ac6a9972 /kernel
parent9e88b9312acb9b80554c48b58668fb144720333a (diff)
downloadlinux-fdbaa0beb78b7c8847e261fe2c32816e9d1c54cc.tar.bz2
bpf: Ensure line_info.insn_off cannot point to insn with zero code
This patch rejects a line_info if the bpf insn code referred by line_info.insn_off is 0. F.e. a broken userspace tool might generate a line_info.insn_off that points to the second 8 bytes of a BPF_LD_IMM64. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/verifier.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index e0e77ffeefb8..5c64281d566e 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4980,6 +4980,14 @@ static int check_btf_line(struct bpf_verifier_env *env,
goto err_free;
}
+ if (!prog->insnsi[linfo[i].insn_off].code) {
+ verbose(env,
+ "Invalid insn code at line_info[%u].insn_off\n",
+ i);
+ err = -EINVAL;
+ goto err_free;
+ }
+
if (!btf_name_by_offset(btf, linfo[i].line_off) ||
!btf_name_by_offset(btf, linfo[i].file_name_off)) {
verbose(env, "Invalid line_info[%u].line_off or .file_name_off\n", i);