af_unix: Remove dead code in unix_stream_read_generic().

When splice() support was added in commit 2b514574f7e8 ("net:
af_unix: implement splice for stream af_unix sockets"), we had
to release unix_sk(sk)->readlock (current iolock) before calling
splice_to_pipe().

Due to the unlock, commit 73ed5d25dce0 ("af-unix: fix use-after-free
with concurrent readers while splicing") added a safeguard in
unix_stream_read_generic(); we had to bump the skb refcount before
calling ->recv_actor() and then check if the skb was consumed by a
concurrent reader.

However, the pipe side locking was refactored, and since commit
25869262ef7a ("skb_splice_bits(): get rid of callback"), we can
call splice_to_pipe() without releasing unix_sk(sk)->iolock.

Now, the skb is always alive after the ->recv_actor() callback,
so let's remove the unnecessary drop_skb logic.

This is mostly the revert of commit 73ed5d25dce0 ("af-unix: fix
use-after-free with concurrent readers while splicing").

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240529144648.68591-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions