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| author | Peilin Ye <yepeilin.cs@gmail.com> | 2020-07-14 14:09:04 -0400 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-07-15 22:53:39 +0200 |
| commit | 5b801dfb7feb2738975d80223efc2fc193e55573 (patch) | |
| tree | b48c46430339fca6903d01995a8c6b5a57a9cf59 /kernel/bpf | |
| parent | 55b244221c3f17eb2ed51c8e39e4a01c523e4eee (diff) | |
| download | lwn-5b801dfb7feb2738975d80223efc2fc193e55573.tar.gz lwn-5b801dfb7feb2738975d80223efc2fc193e55573.zip | |
bpf: Fix NULL pointer dereference in __btf_resolve_helper_id()
Prevent __btf_resolve_helper_id() from dereferencing `btf_vmlinux`
as NULL. This patch fixes the following syzbot bug:
https://syzkaller.appspot.com/bug?id=f823224ada908fa5c207902a5a62065e53ca0fcc
Reported-by: syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200714180904.277512-1-yepeilin.cs@gmail.com
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/btf.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 9a1a98dd9e97..0443600146dc 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4058,6 +4058,11 @@ static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn, const char *tname, *sym; u32 btf_id, i; + if (!btf_vmlinux) { + bpf_log(log, "btf_vmlinux doesn't exist\n"); + return -EINVAL; + } + if (IS_ERR(btf_vmlinux)) { bpf_log(log, "btf_vmlinux is malformed\n"); return -EINVAL; |