5.4-stable review patch. If anyone has any objections, please let me know.
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From: Alexey Simakov bigalex934@gmail.com
[ Upstream commit 441f0647f7673e0e64d4910ef61a5fb8f16bfb82 ]
chunk->skb pointer is dereferenced in the if-block where it's supposed to be NULL only.
chunk->skb can only be NULL if chunk->head_skb is not. Check for frag_list instead and do it just before replacing chunk->skb. We're sure that otherwise chunk->skb is non-NULL because of outer if() condition.
Fixes: 90017accff61 ("sctp: Add GSO support") Signed-off-by: Alexey Simakov bigalex934@gmail.com Acked-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Link: https://patch.msgid.link/20251021130034.6333-1-bigalex934@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/sctp/inqueue.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c index 7182c5a450fb5..6a434d441dc70 100644 --- a/net/sctp/inqueue.c +++ b/net/sctp/inqueue.c @@ -163,13 +163,14 @@ struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue) chunk->head_skb = chunk->skb;
/* skbs with "cover letter" */ - if (chunk->head_skb && chunk->skb->data_len == chunk->skb->len) + if (chunk->head_skb && chunk->skb->data_len == chunk->skb->len) { + if (WARN_ON(!skb_shinfo(chunk->skb)->frag_list)) { + __SCTP_INC_STATS(dev_net(chunk->skb->dev), + SCTP_MIB_IN_PKT_DISCARDS); + sctp_chunk_free(chunk); + goto next_chunk; + } chunk->skb = skb_shinfo(chunk->skb)->frag_list; - - if (WARN_ON(!chunk->skb)) { - __SCTP_INC_STATS(dev_net(chunk->skb->dev), SCTP_MIB_IN_PKT_DISCARDS); - sctp_chunk_free(chunk); - goto next_chunk; } }