On 6/10/21 9:45 AM, Hao Xu wrote:
> Correct wrong use of io_poll_get_single in io_poll_double_wake, which
> I think is a slip-up.
Not really. It removes both poll entries
> [ 55.204528] WARNING: CPU: 0 PID: 2660 at fs/io_uring.c:1512 io_poll_double_wake+0x1d6/0x1f0
> [ 55.204546] Modules linked in:
> [ 55.204560] CPU: 0 PID: 2660 Comm: a.out Not tainted 5.13.0-rc3+ #1
> [ 55.204575] RIP: 0010:io_poll_double_wake+0x1d6/0x1f0
> [ 55.204584] Code: ff 48 89 eb e9 8b fe ff ff e8 c6 68 d3 ff 49 c7 44 24 08 00 00 00 00 48 8b 7b 08 e8 e4 7b 9d 00 e9 5d ff ff ff e8 aa 68 d3 ff <0f> 0b e9 76 ff ff ff e8 9e 68 d3 ff 0f 0b e9 59 ff ff ff 0f 1f 80
> [ 55.204592] RSP: 0018:ffffc90003c73cc8 EFLAGS: 00010093
> [ 55.204599] RAX: 0000000000000000 RBX: ffff88810fcf6500 RCX: 0000000000000000
> [ 55.204604] RDX: ffff88810d38b500 RSI: ffffffff814d3dd6 RDI: ffff88810ff5fd60
> [ 55.204610] RBP: ffff88810fcf6500 R08: ffff88810d38bf38 R09: 00000000fffffffe
> [ 55.204615] R10: 00000000e2886200 R11: 000000005dbbc615 R12: ffff88810d068658
> [ 55.204620] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000040000000
> [ 55.204625] FS: 00007f84d6170700(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
> [ 55.204635] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 55.204640] CR2: 00007f84d616fef8 CR3: 000000010ffd2006 CR4: 00000000001706f0
> [ 55.204646] Call Trace:
> [ 55.204656] __wake_up_common+0x9f/0x1b0
> [ 55.204674] __wake_up_common_lock+0x7a/0xc0
> [ 55.204694] tty_ldisc_lock+0x44/0x80
> [ 55.204705] tty_ldisc_hangup+0xe3/0x240
> [ 55.204719] __tty_hangup+0x26b/0x360
> [ 55.204736] tty_ioctl+0x6be/0xb20
> [ 55.204747] ? do_vfs_ioctl+0x1af/0xaa0
> [ 55.204757] ? __fget_files+0x15a/0x260
> [ 55.204774] ? tty_vhangup+0x20/0x20
> [ 55.204787] __x64_sys_ioctl+0xbb/0x100
> [ 55.204801] do_syscall_64+0x36/0x70
> [ 55.204813] entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Reported-by: Abaci <abaci@xxxxxxxxxxxxxxxxx>
> Fixes: d4e7cd36a90e ("io_uring: sanitize double poll handling")
> Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
> ---
> fs/io_uring.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index b2cc1e76d660..2be2db156094 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -4950,7 +4950,7 @@ static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
> int sync, void *key)
> {
> struct io_kiocb *req = wait->private;
> - struct io_poll_iocb *poll = io_poll_get_single(req);
> + struct io_poll_iocb *poll = io_poll_get_double(req);
> __poll_t mask = key_to_poll(key);
>
> /* for instances that support it check for an event match first: */
>
--
Pavel Begunkov
