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authorDmitry Antipov <dmantipov@yandex.ru>2024-02-14 11:22:24 +0300
committerJakub Kicinski <kuba@kernel.org>2024-02-15 07:34:52 -0800
commit4e45170d9acc2d5ae8f545bf3f2f67504a361338 (patch)
tree4d210c3c697c075f5a7cc30c40efd4beed7d6021
parente5b2e810daf9f2d87fe132eb4d2a85fb08a0db98 (diff)
downloadextcon-4e45170d9acc2d5ae8f545bf3f2f67504a361338.tar.gz
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>
-rw-r--r--net/sctp/inqueue.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c
index 7182c5a450fb5b..5c165218180588 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. */