[syzbot] WARNING: still has locks held in rxrpc_sendmsg

Hello,

syzbot found the following issue on:

HEAD commit:    4c4f0c2bf341 Merge tag 'ceph-for-5.15-rc3' of git://github..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=148a7b5f300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=83fd90919369058f
dashboard link: https://syzkaller.appspot.com/bug?extid=ab47992aa36f7cc43f1b
compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17750c6b300000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14dc8087300000

The issue was bisected to:

commit 4d004099a668c41522242aa146a38cc4eb59cb1e
Author: Peter Zijlstra [off-list ref]
Date:   Fri Oct 2 09:04:21 2020 +0000

    lockdep: Fix lockdep recursion

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=151246d1300000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=171246d1300000
console output: https://syzkaller.appspot.com/x/log.txt?x=131246d1300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ab47992aa36f7cc43f1b@syzkaller.appspotmail.com
Fixes: 4d004099a668 ("lockdep: Fix lockdep recursion")

====================================
WARNING: syz-executor718/13823 still has locks held!
5.15.0-rc2-syzkaller #0 Not tainted
------------------------------------
1 lock held by syz-executor718/13823:
 #0: ffff88815d3d9620 (sk_lock-AF_RXRPC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline]
 #0: ffff88815d3d9620 (sk_lock-AF_RXRPC){+.+.}-{0:0}, at: rxrpc_sendmsg+0x11a/0x8a0 net/rxrpc/af_rxrpc.c:520

stack backtrace:
CPU: 1 PID: 13823 Comm: syz-executor718 Not tainted 5.15.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x201/0x2d8 lib/dump_stack.c:106
 try_to_freeze include/linux/freezer.h:66 [inline]
 get_signal+0x185/0x20c0 kernel/signal.c:2663
 arch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300
 do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe10f2acb59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe10f25d208 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: fffffffffffffe00 RBX: 00007fe10f3343e8 RCX: 00007fe10f2acb59
RDX: 0000000000000001 RSI: 0000000020001900 RDI: 0000000000000003
RBP: 00007fe10f3343e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe10f3343ec
R13: 00007ffdce01da0f R14: 00007fe10f25d300 R15: 0000000000022000


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