Datagram fragment iteration helpers check for invalid buffer offsets using WARN_ON(). In fast-path packet processing routines, a malformed skb or lower-level driver bug triggering this check can result in unbounded dmesg logging. Excessive console logging in data-path contexts introduces severe I/O latency overhead and risks triggering a DoS or system instability via log flooding. Replace WARN_ON() with WARN_ON_ONCE() in __skb_datagram_iter() and skb_copy_datagram_from_iter(). This ensures anomalous conditions remain reportable for debugging without spamming the kernel log on repeated occurrences. Signed-off-by: Igor Putko --- net/core/datagram.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/core/datagram.c b/net/core/datagram.c index c285c6465..125b52870 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -416,7 +416,7 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset, int end; const skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; - WARN_ON(start > offset + len); + WARN_ON_ONCE(start > offset + len); end = start + skb_frag_size(frag); if ((copy = end - offset) > 0) { @@ -449,7 +449,7 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset, skb_walk_frags(skb, frag_iter) { int end; - WARN_ON(start > offset + len); + WARN_ON_ONCE(start > offset + len); end = start + frag_iter->len; if ((copy = end - offset) > 0) { @@ -570,7 +570,7 @@ int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, int end; const skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; - WARN_ON(start > offset + len); + WARN_ON_ONCE(start > offset + len); end = start + skb_frag_size(frag); if ((copy = end - offset) > 0) { @@ -594,7 +594,7 @@ int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, skb_walk_frags(skb, frag_iter) { int end; - WARN_ON(start > offset + len); + WARN_ON_ONCE(start > offset + len); end = start + frag_iter->len; if ((copy = end - offset) > 0) { -- 2.47.3