linux-stable.git/fs/io_uring.c, branch v5.18

io_uring: don't attempt to IOPOLL for MSG_RING requests

2022-05-17T18:46:04+00:00

We gate whether to IOPOLL for a request on whether the opcode is allowed
on a ring setup for IOPOLL and if it's got a file assigned. MSG_RING
is the only one that allows a file yet isn't pollable, it's merely
supported to allow communication on an IOPOLL ring, not because we can
poll for completion of it.

Put the assigned file early and clear it, so we don't attempt to poll
for it.

Reported-by: syzbot+1a0a53300ce782f8b3ad@syzkaller.appspotmail.com
Fixes: 3f1d52abf098 ("io_uring: defer msg-ring file validity check until command issue")
Signed-off-by: Jens Axboe

io_uring: assign non-fixed early for async work

2022-05-02T14:09:39+00:00

We defer file assignment to ensure that fixed files work with links
between a direct accept/open and the links that follow it. But this has
the side effect that normal file assignment is then not complete by the
time that request submission has been done.

For deferred execution, if the file is a regular file, assign it when
we do the async prep anyway.

Signed-off-by: Jens Axboe

io_uring: check that data field is 0 in ringfd unregister

2022-04-29T14:39:43+00:00

Only allow data field to be 0 in struct io_uring_rsrc_update user
arguments to allow for future possible usage.

Fixes: e7a6c00dc77a ("io_uring: add support for registering ring file descriptors")
Signed-off-by: Eugene Syromiatnikov 
Link: https://lore.kernel.org/r/20220429142218.GA28696@asgard.redhat.com
Signed-off-by: Jens Axboe

io_uring: fix uninitialized field in rw io_kiocb

2022-04-28T19:13:43+00:00

io_rw_init_file does not initialize kiocb->private, so when iocb_bio_iopoll
reads kiocb->private it can contain uninitialized data.

Fixes: 3e08773c3841 ("block: switch polling to be bio based")
Signed-off-by: Joseph Ravichandran 
Signed-off-by: Jens Axboe

io_uring: check reserved fields for recv/recvmsg

2022-04-27T02:48:37+00:00

We should check unused fields for non-zero and -EINVAL if they are set,
making it consistent with other opcodes.

Fixes: aa1fa28fc73e ("io_uring: add support for recvmsg()")
Signed-off-by: Jens Axboe

io_uring: check reserved fields for send/sendmsg

2022-04-27T02:48:31+00:00

We should check unused fields for non-zero and -EINVAL if they are set,
making it consistent with other opcodes.

Fixes: 0fa03c624d8f ("io_uring: add support for sendmsg()")
Signed-off-by: Jens Axboe

io_uring: fix leaks on IOPOLL and CQE_SKIP

2022-04-17T12:54:11+00:00

If all completed requests in io_do_iopoll() were marked with
REQ_F_CQE_SKIP, we'll not only skip CQE posting but also
io_free_batch_list() leaking memory and resources.

Move @nr_events increment before REQ_F_CQE_SKIP check. We'll potentially
return the value greater than the real one, but iopolling will deal with
it and the userspace will re-iopoll if needed. In anyway, I don't think
there are many use cases for REQ_F_CQE_SKIP + IOPOLL.

Fixes: 83a13a4181b0e ("io_uring: tweak iopoll CQE_SKIP event counting")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/5072fc8693fbfd595f89e5d4305bfcfd5d2f0a64.1650186611.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring: free iovec if file assignment fails

2022-04-17T03:14:00+00:00

We just return failure in this case, but we need to release the iovec
first. If we're doing IO with more than FAST_IOV segments, then the
iovec is allocated and must be freed.

Reported-by: syzbot+96b43810dfe9c3bb95ed@syzkaller.appspotmail.com
Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler")
Signed-off-by: Jens Axboe

io_uring: abort file assignment prior to assigning creds

2022-04-15T02:23:40+00:00

We need to either restore creds properly if we fail on the file
assignment, or just do the file assignment first instead. Let's do
the latter as it's simpler, should make no difference here for
file assignment.

Link: https://lore.kernel.org/lkml/000000000000a7edb305dca75a50@google.com/
Reported-by: syzbot+60c52ca98513a8760a91@syzkaller.appspotmail.com
Fixes: 6bf9c47a3989 ("io_uring: defer file assignment")
Signed-off-by: Jens Axboe

io_uring: fix poll error reporting

2022-04-13T16:25:37+00:00

We should not return an error code in req->result in
io_poll_check_events(), because it may get mangled and returned as
success. Just return the error code directly, the callers will fail the
request or proceed accordingly.

Fixes: 6bf9c47a3989 ("io_uring: defer file assignment")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/5f03514ee33324dc811fb93df84aee0f695fb044.1649862516.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe