diff mbox series

[v2,net-next,4/5] net: remove two BUG() from skb_checksum_help()

Message ID 20220510035741.2807829-5-eric.dumazet@gmail.com (mailing list archive)
State Accepted
Commit d7ea0d9df2a6265b2b180d17ebc64b38105968fc
Delegated to: Netdev Maintainers
Headers show
Series net: CONFIG_DEBUG_NET and friends | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 7 this patch: 7
netdev/cc_maintainers warning 1 maintainers not CCed: petrm@nvidia.com
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 7 this patch: 7
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 17 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet May 10, 2022, 3:57 a.m. UTC 
From: Eric Dumazet <edumazet@google.com>

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>
---
 net/core/dev.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index f036ccb61da4da3ffc52c4f2402427054b831e8a..e12f8310dd86b312092c5d8fd50fa2ab60fce310 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3265,11 +3265,15 @@  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)