[Linux-kernel-mentees] [PATCH] bpf: Fix NULL pointer dereference in __btf_resolve_helper_id()
From: Peilin Ye <hidden>
Date: 2020-07-14 00:42:32
Also in:
bpf, lkml, netdev
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Prevent __btf_resolve_helper_id() from dereferencing `btf_vmlinux`
as NULL. This patch fixes the following syzbot bug:
https://syzkaller.appspot.com/bug?id=5edd146856fd513747c1992442732e5a0e9ba355
Reported-by: syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com
Signed-off-by: Peilin Ye <redacted>
---
kernel/bpf/btf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 30721f2c2d10..3e981b183fa4 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c@@ -4088,7 +4088,7 @@ static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn, const char *tname, *sym; u32 btf_id, i; - if (IS_ERR(btf_vmlinux)) { + if (IS_ERR_OR_NULL(btf_vmlinux)) { bpf_log(log, "btf_vmlinux is malformed\n"); return -EINVAL; }
--
2.25.1
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