[syzbot] [ext4?] BUG: sleeping function called from invalid context in jbd2_journal_commit_transaction

[syzbot] [ext4?] BUG: sleeping function called from invalid context in jbd2_journal_commit_transaction

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    6596a02b2078 Merge tag 'drm-next-2026-04-22' of https://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=120d3702580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=80b28e8d6ef9384a
dashboard link: https://syzkaller.appspot.com/bug?extid=06294fd562f060379c91
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5b2b3122db47/disk-6596a02b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7ee12b37f6e5/vmlinux-6596a02b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/aca25073993c/bzImage-6596a02b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+06294fd562f060379c91@syzkaller.appspotmail.com

BUG: sleeping function ca[   92.150581][ T5155] BUG: sleeping function called from invalid context at fs/jbd2/commit.c:1071
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5155, name: jbd2/sda1-8
preempt_count: 0, expected: 0
RCU nest depth: 2, expected: 1
3 locks held by jbd2/sda1-8/5155:
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
 #1: ffff888036ea4920 (&journal->j_list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #1: ffff888036ea4920 (&journal->j_list_lock){+.+.}-{3:3}, at: jbd2_journal_commit_transaction+0x3ad1/0x5b20 fs/jbd2/commit.c:993
 #2: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #2: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #2: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
CPU: 0 UID: 0 PID: 5155 Comm: jbd2/sda1-8 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 __might_resched+0x329/0x480 kernel/sched/core.c:9162
 jbd2_journal_commit_transaction+0x3f59/0x5b20 fs/jbd2/commit.c:1071
 kjournald2+0x3e0/0x760 fs/jbd2/journal.c:201
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
------------[ cut here ]------------
Voluntary context switch within RCU read-side critical section!
WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0xcac/0xf40 kernel/rcu/tree_plugin.h:332, CPU#0: jbd2/sda1-8/5155
Modules linked in:
CPU: 0 UID: 0 PID: 5155 Comm: jbd2/sda1-8 Tainted: G        W           syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:rcu_note_context_switch+0xcac/0xf40 kernel/rcu/tree_plugin.h:332
Code: 00 41 c6 45 00 00 48 8b 3d a1 20 e1 0d 48 81 c4 b8 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d e9 bb 5f ff ff 48 8d 3d a4 e2 e4 0d <67> 48 0f b9 3a e9 1b f4 ff ff 90 0f 0b 90 45 84 e4 0f 84 ea f3 ff
RSP: 0018:ffffc90010177930 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffff888036ec5c40 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8ba74040 RDI: ffffffff8f8f3dd0
RBP: dffffc0000000000 R08: ffffffff8f8bcef7 R09: 1ffffffff1f179de
R10: dffffc0000000000 R11: fffffbfff1f179df R12: 0000000000000000
R13: dffffc0000000000 R14: ffff8880b883c800 R15: ffff888036ec6104
FS:  0000000000000000(0000) GS:ffff8881260fb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557df50340 CR3: 0000000011b24000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __schedule+0x291/0x54c0 kernel/sched/core.c:7043
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7282
 kjournald2+0x410/0x760 fs/jbd2/journal.c:230
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 41 c6             	add    %al,-0x3a(%rcx)
   3:	45 00 00             	add    %r8b,(%r8)
   6:	48 8b 3d a1 20 e1 0d 	mov    0xde120a1(%rip),%rdi        # 0xde120ae
   d:	48 81 c4 b8 00 00 00 	add    $0xb8,%rsp
  14:	5b                   	pop    %rbx
  15:	41 5c                	pop    %r12
  17:	41 5d                	pop    %r13
  19:	41 5e                	pop    %r14
  1b:	41 5f                	pop    %r15
  1d:	5d                   	pop    %rbp
  1e:	e9 bb 5f ff ff       	jmp    0xffff5fde
  23:	48 8d 3d a4 e2 e4 0d 	lea    0xde4e2a4(%rip),%rdi        # 0xde4e2ce
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 1b f4 ff ff       	jmp    0xfffff44f
  34:	90                   	nop
  35:	0f 0b                	ud2
  37:	90                   	nop
  38:	45 84 e4             	test   %r12b,%r12b
  3b:	0f                   	.byte 0xf
  3c:	84 ea                	test   %ch,%dl
  3e:	f3                   	repz
  3f:	ff                   	.byte 0xff


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