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| author | Dmitry Antipov <dmantipov@yandex.ru> | 2024-02-14 11:22:24 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-02-15 07:34:52 -0800 |
| commit | 4e45170d9acc2d5ae8f545bf3f2f67504a361338 (patch) | |
| tree | 4d210c3c697c075f5a7cc30c40efd4beed7d6021 /net/sctp | |
| parent | e5b2e810daf9f2d87fe132eb4d2a85fb08a0db98 (diff) | |
| download | lwn-4e45170d9acc2d5ae8f545bf3f2f67504a361338.tar.gz lwn-4e45170d9acc2d5ae8f545bf3f2f67504a361338.zip | |
net: sctp: fix skb leak in sctp_inq_free()
In case of GSO, 'chunk->skb' pointer may point to an entry from
fraglist created in 'sctp_packet_gso_append()'. To avoid freeing
random fraglist entry (and so undefined behavior and/or memory
leak), introduce 'sctp_inq_chunk_free()' helper to ensure that
'chunk->skb' is set to 'chunk->head_skb' (i.e. fraglist head)
before calling 'sctp_chunk_free()', and use the aforementioned
helper in 'sctp_inq_pop()' as well.
Reported-by: syzbot+8bb053b5d63595ab47db@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?id=0d8351bbe54fd04a492c2daab0164138db008042
Fixes: 90017accff61 ("sctp: Add GSO support")
Suggested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/20240214082224.10168-1-dmantipov@yandex.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/inqueue.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c index 7182c5a450fb..5c1652181805 100644 --- a/net/sctp/inqueue.c +++ b/net/sctp/inqueue.c @@ -38,6 +38,14 @@ void sctp_inq_init(struct sctp_inq *queue) INIT_WORK(&queue->immediate, NULL); } +/* Properly release the chunk which is being worked on. */ +static inline void sctp_inq_chunk_free(struct sctp_chunk *chunk) +{ + if (chunk->head_skb) + chunk->skb = chunk->head_skb; + sctp_chunk_free(chunk); +} + /* Release the memory associated with an SCTP inqueue. */ void sctp_inq_free(struct sctp_inq *queue) { @@ -53,7 +61,7 @@ void sctp_inq_free(struct sctp_inq *queue) * free it as well. */ if (queue->in_progress) { - sctp_chunk_free(queue->in_progress); + sctp_inq_chunk_free(queue->in_progress); queue->in_progress = NULL; } } @@ -130,9 +138,7 @@ struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue) goto new_skb; } - if (chunk->head_skb) - chunk->skb = chunk->head_skb; - sctp_chunk_free(chunk); + sctp_inq_chunk_free(chunk); chunk = queue->in_progress = NULL; } else { /* Nothing to do. Next chunk in the packet, please. */ |