[syzbot] WARNING: suspicious RCU usage in write_inode_now

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    4b97bac0756a Merge tag 'for-5.18-rc5-tag' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=155ed341f00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f179a672dc8535fc
dashboard link: https://syzkaller.appspot.com/bug?extid=8c4c9140d0ef91aaad3f
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8c4c9140d0ef91aaad3f@xxxxxxxxxxxxxxxxxxxxxxxxx

=============================
WARNING: suspicious RCU usage
5.18.0-rc5-syzkaller-00163-g4b97bac0756a #0 Not tainted
-----------------------------
kernel/sched/core.c:9701 Illegal context switch in RCU-bh read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor.3/10437:
 #0: ffff88801afc60e0 (&type->s_umount_key#86/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xa80 fs/super.c:228

stack backtrace:
CPU: 0 PID: 10437 Comm: syz-executor.3 Not tainted 5.18.0-rc5-syzkaller-00163-g4b97bac0756a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 __might_resched+0x235/0x2c0 kernel/sched/core.c:9701
 write_inode_now+0x14a/0x1d0 fs/fs-writeback.c:2696
 iput_final fs/inode.c:1731 [inline]
 iput.part.0+0x460/0x820 fs/inode.c:1770
 iput+0x58/0x70 fs/inode.c:1760
 ntfs_fill_super+0x2e08/0x37b0 fs/ntfs3/super.c:1178
 get_tree_bdev+0x440/0x760 fs/super.c:1292
 vfs_get_tree+0x89/0x2f0 fs/super.c:1497
 do_new_mount fs/namespace.c:3040 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount fs/namespace.c:3568 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f1ac9a8a61a
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1acacb4f88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f1ac9a8a61a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f1acacb4fe0
RBP: 00007f1acacb5020 R08: 00007f1acacb5020 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f1acacb4fe0 R15: 000000002007c6a0
 </TASK>


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