BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:323
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 50, name: kworker/u8:4
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u8:4/50:
#0: ffff888100e9d140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc90000537d18 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffff8881012bc0d8 (&type->s_umount_key#33){.+.+}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:565
#3: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: unlocked_inode_to_wb_begin include/linux/backing-dev.h:290 [inline]
#3: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: folio_clear_dirty_for_io+0x1eb/0x7f0 mm/page-writeback.c:2919
CPU: 0 UID: 0 PID: 50 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
__might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9162
might_alloc include/linux/sched/mm.h:323 [inline]
might_alloc include/linux/sched/mm.h:315 [inline]
mempool_alloc_noprof+0x220/0x310 mm/mempool.c:558
bio_alloc_bioset+0x8d5/0x1050 block/bio.c:594
bio_alloc include/linux/bio.h:367 [inline]
submit_bh_wbc+0x250/0x710 fs/buffer.c:2716
__block_write_full_folio+0x77f/0xee0 fs/buffer.c:1830
block_write_full_folio+0x3b5/0x4e0 fs/buffer.c:2650
blkdev_writepages+0xc7/0x150 block/fops.c:486
do_writepages+0x278/0x600 mm/page-writeback.c:2575
__writeback_single_inode+0x164/0x1350 fs/fs-writeback.c:1764
writeback_sb_inodes+0x766/0x1c60 fs/fs-writeback.c:2056
__writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2132
wb_writeback+0x720/0xb90 fs/fs-writeback.c:2243
wb_check_old_data_flush fs/fs-writeback.c:2347 [inline]
wb_do_writeback fs/fs-writeback.c:2400 [inline]
wb_workfn+0x8dd/0xc00 fs/fs-writeback.c:2428
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
BUG: workqueue leaked atomic, lock or RCU: kworker/u8:4[50]
preempt=0x00000000 lock=0->1 RCU=0->1 workfn=wb_workfn
1 lock held by kworker/u8:4/50:
#0:
ffffffff896de8e0
(
rcu_read_lock
){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
){....}-{1:3}, at: unlocked_inode_to_wb_begin include/linux/backing-dev.h:290 [inline]
){....}-{1:3}, at: folio_clear_dirty_for_io+0x1eb/0x7f0 mm/page-writeback.c:2919
CPU: 0 UID: 0 PID: 50 Comm: kworker/u8:4 Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
process_one_work.cold+0x127/0x306 kernel/workqueue.c:3323
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
=============================
[ BUG: Invalid wait context ]
syzkaller #0 Tainted: G W
-----------------------------
kworker/u8:4/50 is trying to lock:
ffff88811bb071d0 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x45a/0xd30 fs/ext4/inode.c:823
other info that might help us debug this:
context-{5:5}
4 locks held by kworker/u8:4/50:
#0: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: unlocked_inode_to_wb_begin include/linux/backing-dev.h:290 [inline]
#0: ffffffff896de8e0 (rcu_read_lock){....}-{1:3}, at: folio_clear_dirty_for_io+0x1eb/0x7f0 mm/page-writeback.c:2919
#1: ffff888113550940 ((wq_completion)ext4-rsv-conversion){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#2: ffffc90000537d18 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#3: ffff888116262938 (jbd2_handle){.+.+}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
stack backtrace:
CPU: 0 UID: 0 PID: 50 Comm: kworker/u8:4 Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline]
check_wait_context kernel/locking/lockdep.c:4902 [inline]
__lock_acquire+0xfa4/0x2630 kernel/locking/lockdep.c:5187
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825
down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1625
ext4_map_blocks+0x45a/0xd30 fs/ext4/inode.c:823
ext4_convert_unwritten_extents+0x2a6/0x4d0 fs/ext4/extents.c:5067
ext4_convert_unwritten_io_end_vec+0x121/0x280 fs/ext4/extents.c:5107
ext4_end_io_end+0xd3/0x4b0 fs/ext4/page-io.c:199
ext4_do_flush_completed_IO fs/ext4/page-io.c:290 [inline]
ext4_end_io_rsv_work+0x205/0x380 fs/ext4/page-io.c:305
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:323
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 50, name: kworker/u8:4
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
CPU: 0 UID: 0 PID: 50 Comm: kworker/u8:4 Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
__might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9162
might_alloc include/linux/sched/mm.h:323 [inline]
slab_pre_alloc_hook mm/slub.c:4520 [inline]
slab_alloc_node mm/slub.c:4875 [inline]
__do_kmalloc_node mm/slub.c:5294 [inline]
__kmalloc_noprof+0x55e/0x810 mm/slub.c:5307
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
ext4_find_extent+0x21b/0xa30 fs/ext4/extents.c:918
ext4_ext_map_blocks+0x20a/0x5930 fs/ext4/extents.c:4286
ext4_map_create_blocks+0xec/0x5e0 fs/ext4/inode.c:631
ext4_map_blocks+0x46b/0xd30 fs/ext4/inode.c:824
ext4_convert_unwritten_extents+0x2a6/0x4d0 fs/ext4/extents.c:5067
ext4_convert_unwritten_io_end_vec+0x121/0x280 fs/ext4/extents.c:5107
ext4_end_io_end+0xd3/0x4b0 fs/ext4/page-io.c:199
ext4_do_flush_completed_IO fs/ext4/page-io.c:290 [inline]
ext4_end_io_rsv_work+0x205/0x380 fs/ext4/page-io.c:305
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
BUG: workqueue leaked atomic, lock or RCU: kworker/u8:4[50]
preempt=0x00000000 lock=1->0 RCU=1->1 workfn=ext4_end_io_rsv_work
INFO: lockdep is turned off.
CPU: 0 UID: 0 PID: 50 Comm: kworker/u8:4 Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
process_one_work.cold+0x127/0x306 kernel/workqueue.c:3323
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
------------[ cut here ]------------
Voluntary context switch within RCU read-side critical section!
WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x859/0x19c0 kernel/rcu/tree_plugin.h:332, CPU#0: kworker/u8:4/50
Modules linked in:
CPU: 0 UID: 0 PID: 50 Comm: kworker/u8:4 Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: 0x0 (ext4-rsv-conversion)
RIP: 0010:rcu_note_context_switch+0x859/0x19c0 kernel/rcu/tree_plugin.h:332
Code: c1 ea 03 80 3c 02 00 0f 85 9b 0b 00 00 48 8b 53 28 b9 01 00 00 00 4c 89 ef e8 a3 cf fe ff e9 1d f9 ff ff 48 8d 3d 27 29 59 09 <67> 48 0f b9 3a e9 99 f8 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8d
RSP: 0018:ffffc90000537c10 EFLAGS: 00010002
RAX: 0000000000000001 RBX: ffff8881f563a540 RCX: ffffffff81987a21
RDX: 0000000000000000 RSI: ffffffff87b08ce0 RDI: ffffffff8af21770
RBP: ffff888103eb8000 R08: 0000000000000000 R09: fffffbfff15e10da
R10: ffffffff8af086d7 R11: 0000000000000001 R12: 0000000000000000
R13: ffff888103eb847c R14: ffffffff8cf91680 R15: ffffffff8af09664
FS: 0000000000000000(0000) GS:ffff8882686a8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d53982e008 CR3: 0000000117564000 CR4: 00000000003506f0
Call Trace:
__schedule+0x25e/0x4840 kernel/sched/core.c:7043
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
worker_thread+0x53b/0xe50 kernel/workqueue.c:3481
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: c1 ea 03 shr $0x3,%edx
3: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
7: 0f 85 9b 0b 00 00 jne 0xba8
d: 48 8b 53 28 mov 0x28(%rbx),%rdx
11: b9 01 00 00 00 mov $0x1,%ecx
16: 4c 89 ef mov %r13,%rdi
19: e8 a3 cf fe ff call 0xfffecfc1
1e: e9 1d f9 ff ff jmp 0xfffff940
23: 48 8d 3d 27 29 59 09 lea 0x9592927(%rip),%rdi # 0x9592951
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: e9 99 f8 ff ff jmp 0xfffff8cd
34: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
3b: fc ff df
3e: 48 rex.W
3f: 8d .byte 0x8d