[syzbot] possible deadlock in rds_message_put

[syzbot <syzbot+f9db6ff27b9bfdcfeca0@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    c183e6c3ec34 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1161aa7c480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8ca07260bb631fb4
dashboard link: https://syzkaller.appspot.com/bug?extid=f9db6ff27b9bfdcfeca0
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1370b478480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17ab141a480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9b693820fb05/disk-c183e6c3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e449d80e60dc/vmlinux-c183e6c3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/08e31763ce79/bzImage-c183e6c3.xz

The issue was bisected to:

commit 1628c6877f371194b603330c324828d03e0eacda
Author: Jason Wang <jasowang@redhat.com>
Date:   Mon Jan 4 06:55:02 2021 +0000

    virtio_vdpa: don't warn when fail to disable vq

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1479f7da480000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=1679f7da480000
console output: https://syzkaller.appspot.com/x/log.txt?x=1279f7da480000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f9db6ff27b9bfdcfeca0@syzkaller.appspotmail.com
Fixes: 1628c6877f37 ("virtio_vdpa: don't warn when fail to disable vq")

======================================================
WARNING: possible circular locking dependency detected
6.1.0-syzkaller-11778-gc183e6c3ec34 #0 Not tainted
------------------------------------------------------
syz-executor390/18169 is trying to acquire lock:
ffff8880763af100 (&rm->m_rs_lock){..-.}-{2:2}, at: rds_message_purge net/rds/message.c:138 [inline]
ffff8880763af100 (&rm->m_rs_lock){..-.}-{2:2}, at: rds_message_put+0x1dd/0xc20 net/rds/message.c:180

but task is already holding lock:
ffff88802afafa70 (&rs->rs_recv_lock){...-}-{2:2}, at: rds_clear_recv_queue+0x33/0x350 net/rds/recv.c:761

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&rs->rs_recv_lock){...-}-{2:2}:
       __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
       _raw_read_lock_irqsave+0x49/0x90 kernel/locking/spinlock.c:236
       rds_wake_sk_sleep+0x23/0xe0 net/rds/af_rds.c:109
       rds_send_remove_from_sock+0xb9/0x9e0 net/rds/send.c:634
       rds_send_path_drop_acked+0x2f3/0x3d0 net/rds/send.c:710
       rds_tcp_write_space+0x1b5/0x690 net/rds/tcp_send.c:198
       tcp_new_space net/ipv4/tcp_input.c:5483 [inline]
       tcp_check_space+0x11b/0x810 net/ipv4/tcp_input.c:5502
       tcp_data_snd_check net/ipv4/tcp_input.c:5511 [inline]
       tcp_rcv_established+0x93e/0x2230 net/ipv4/tcp_input.c:6019
       tcp_v4_do_rcv+0x670/0x9b0 net/ipv4/tcp_ipv4.c:1721
       sk_backlog_rcv include/net/sock.h:1113 [inline]
       __release_sock+0x133/0x3b0 net/core/sock.c:2928
       release_sock+0x58/0x1b0 net/core/sock.c:3485
       rds_send_xmit+0xafc/0x2540 net/rds/send.c:422
       rds_sendmsg+0x27d3/0x3080 net/rds/send.c:1381
       sock_sendmsg_nosec net/socket.c:714 [inline]
       sock_sendmsg+0xd3/0x120 net/socket.c:734
       __sys_sendto+0x23a/0x340 net/socket.c:2117
       __do_sys_sendto net/socket.c:2129 [inline]
       __se_sys_sendto net/socket.c:2125 [inline]
       __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2125
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&rm->m_rs_lock){..-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain kernel/locking/lockdep.c:3831 [inline]
       __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
       lock_acquire kernel/locking/lockdep.c:5668 [inline]
       lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
       rds_message_purge net/rds/message.c:138 [inline]
       rds_message_put+0x1dd/0xc20 net/rds/message.c:180
       rds_inc_put net/rds/recv.c:82 [inline]
       rds_inc_put+0x13e/0x1a0 net/rds/recv.c:76
       rds_clear_recv_queue+0x14b/0x350 net/rds/recv.c:767
       rds_release+0xd8/0x3c0 net/rds/af_rds.c:73
       __sock_release+0xcd/0x280 net/socket.c:650
       sock_close+0x1c/0x20 net/socket.c:1365
       __fput+0x27c/0xa90 fs/file_table.c:320
       task_work_run+0x16f/0x270 kernel/task_work.c:179
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
       exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
       __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
       syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
       do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rs->rs_recv_lock);
                               lock(&rm->m_rs_lock);
                               lock(&rs->rs_recv_lock);
  lock(&rm->m_rs_lock);

 *** DEADLOCK ***

2 locks held by syz-executor390/18169:
 #0: ffff8880719a3210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #0: ffff8880719a3210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:649
 #1: ffff88802afafa70 (&rs->rs_recv_lock){...-}-{2:2}, at: rds_clear_recv_queue+0x33/0x350 net/rds/recv.c:761

stack backtrace:
CPU: 0 PID: 18169 Comm: syz-executor390 Not tainted 6.1.0-syzkaller-11778-gc183e6c3ec34 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177
 check_prev_add kernel/locking/lockdep.c:3097 [inline]
 check_prevs_add kernel/locking/lockdep.c:3216 [inline]
 validate_chain kernel/locking/lockdep.c:3831 [inline]
 __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
 lock_acquire kernel/locking/lockdep.c:5668 [inline]
 lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
 rds_message_purge net/rds/message.c:138 [inline]
 rds_message_put+0x1dd/0xc20 net/rds/message.c:180
 rds_inc_put net/rds/recv.c:82 [inline]
 rds_inc_put+0x13e/0x1a0 net/rds/recv.c:76
 rds_clear_recv_queue+0x14b/0x350 net/rds/recv.c:767
 rds_release+0xd8/0x3c0 net/rds/af_rds.c:73
 __sock_release+0xcd/0x280 net/socket.c:650
 sock_close+0x1c/0x20 net/socket.c:1365
 __fput+0x27c/0xa90 fs/file_table.c:320
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4a3a75f5fb
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 03 fd ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 41 fd ff ff 8b 44
RSP: 002b:00007ffff26fde60 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f4a3a75f5fb
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000032 R08: 0000000000000000 R09: 00007f4a3a7f51ae
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f4a3a8284ec
R13: 00007ffff26fdeb0 R14: 00007ffff26fded0 R15: 00007ffff26fdf40
 </TASK>


---
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