| a22730b1 | 12-Sep-2023 |
Kuniyuki Iwashima <kuniyu@amazon.com> |
kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg().
syzkaller found a memory leak in kcm_sendmsg(), and commit c821a88bd720
("kcm: Fix memory leak in error path of kcm_sendmsg()") suppressed it
kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg().
syzkaller found a memory leak in kcm_sendmsg(), and commit c821a88bd720
("kcm: Fix memory leak in error path of kcm_sendmsg()") suppressed it by
updating kcm_tx_msg(head)->last_skb if partial data is copied so that the
following sendmsg() will resume from the skb.
However, we cannot know how many bytes were copied when we get the error.
Thus, we could mess up the MSG_MORE queue.
When kcm_sendmsg() fails for SOCK_DGRAM, we should purge the queue as we
do so for UDP by udp_flush_pending_frames().
Even without this change, when the error occurred, the following sendmsg()
resumed from a wrong skb and the queue was messed up. However, we have
yet to get such a report, and only syzkaller stumbled on it. So, this
can be changed safely.
Note this does not change SOCK_SEQPACKET behaviour.
Fixes: c821a88bd720 ("kcm: Fix memory leak in error path of kcm_sendmsg()")
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230912022753.33327-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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| c31a25e1 | 09-Jun-2023 |
David Howells <dhowells@redhat.com> |
kcm: Send multiple frags in one sendmsg()
Rewrite the AF_KCM transmission loop to send all the fragments in a single
skb or frag_list-skb in one sendmsg() with MSG_SPLICE_PAGES set. The list
of fra
kcm: Send multiple frags in one sendmsg()
Rewrite the AF_KCM transmission loop to send all the fragments in a single
skb or frag_list-skb in one sendmsg() with MSG_SPLICE_PAGES set. The list
of fragments in each skb is conveniently a bio_vec[] that can just be
attached to a BVEC iter.
Note: I'm working out the size of each fragment-skb by adding up bv_len for
all the bio_vecs in skb->frags[] - but surely this information is recorded
somewhere? For the skbs in head->frag_list, this is equal to
skb->data_len, but not for the head. head->data_len includes all the tail
frags too.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Tom Herbert <tom@herbertland.com>
cc: Tom Herbert <tom@quantonium.net>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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| 5bb3a5cb | 31-May-2023 |
David Howells <dhowells@redhat.com> |
kcm: Convert kcm_sendpage() to use MSG_SPLICE_PAGES
Convert kcm_sendpage() to use sendmsg() with MSG_SPLICE_PAGES rather than
directly splicing in the pages itself.
This allows ->sendpage() to be r
kcm: Convert kcm_sendpage() to use MSG_SPLICE_PAGES
Convert kcm_sendpage() to use sendmsg() with MSG_SPLICE_PAGES rather than
directly splicing in the pages itself.
This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Tom Herbert <tom@herbertland.com>
cc: Tom Herbert <tom@quantonium.net>
cc: Cong Wang <cong.wang@bytedance.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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