From: Eric Dumazet edumazet@google.com
stable inclusion from stable-v5.10.121 commit 312c43e98ed190bd8fd7a71a0addf9539d5b8ab1 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit d7ea0d9df2a6265b2b180d17ebc64b38105968fc ]
I have a syzbot report that managed to get a crash in skb_checksum_help()
If syzbot can trigger these BUG(), it makes sense to replace them with more friendly WARN_ON_ONCE() since skb_checksum_help() can instead return an error code.
Note that syzbot will still crash there, until real bug is fixed.
Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- net/core/dev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c index 8e4de36eede8..ee0b405681db 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3242,11 +3242,15 @@ int skb_checksum_help(struct sk_buff *skb) }
offset = skb_checksum_start_offset(skb); - BUG_ON(offset >= skb_headlen(skb)); + ret = -EINVAL; + if (WARN_ON_ONCE(offset >= skb_headlen(skb))) + goto out; + csum = skb_checksum(skb, offset, skb->len - offset, 0);
offset += skb->csum_offset; - BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb)); + if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) + goto out;
ret = skb_ensure_writable(skb, offset + sizeof(__sum16)); if (ret)