INFO: task syz-executor:4174 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22256 pid: 4174 ppid:  4173 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit kernel/sched/wait_bit.c:49 [inline]
 out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116
 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251
 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235
 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866
 __ext4_mark_inode_dirty+0x13b/0x6c0 fs/ext4/inode.c:6050
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6087
 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480
 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881
 inode_update_time fs/inode.c:1894 [inline]
 file_update_time+0x3c0/0x440 fs/inode.c:2083
 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6205
 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922
 wp_page_shared+0x163/0x6c0 mm/memory.c:3259
 handle_pte_fault mm/memory.c:4668 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1fbd/0x4440 mm/memory.c:4883
 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f452ed97ae2
RSP: 002b:00007fffd4a01200 EFLAGS: 00010202
RAX: 00007f452ce33000 RBX: 000055557fcda400 RCX: 0000000000000006
RDX: 0000000000003f90 RSI: 000055557fce0010 RDI: 0000000000000040
RBP: 00007fffd4a01700 R08: 000055557fce0258 R09: 0000000000000087
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fffd4a01540
R13: 00007fffd4a01330 R14: 585858582e7a7973 R15: 00007fffd4a01280
 </TASK>
INFO: task syz.5.1567:8671 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1567      state:D stack:27664 pid: 8671 ppid:  6510 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit kernel/sched/wait_bit.c:49 [inline]
 out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116
 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251
 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235
 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866
 __ext4_mark_inode_dirty+0x13b/0x6c0 fs/ext4/inode.c:6050
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6087
 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480
 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881
 inode_update_time fs/inode.c:1894 [inline]
 file_update_time+0x3c0/0x440 fs/inode.c:2083
 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6205
 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922
 do_shared_fault mm/memory.c:4328 [inline]
 do_fault mm/memory.c:4396 [inline]
 handle_pte_fault mm/memory.c:4650 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883
 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f6818715ba9
RSP: 002b:00007ffc5cb16120 EFLAGS: 00010202
RAX: 0000001b32b16000 RBX: ffffffff83a9ac4a RCX: 0000001b32b15ff8
RDX: 0000001b32524220 RSI: 0000000000000008 RDI: 00007f68195f8720
RBP: 000000000000010d R08: 00007f6818ab3000 R09: 00007f6818ab5000
R10: 0000000083a9ac4e R11: 0000000000000002 R12: 00007f6818ac9038
R13: 000000000000029d R14: ffffffff83a9a07f R15: 00007f68195f8720
 </TASK>
INFO: task syz.6.1608:8768 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1608      state:D stack:27408 pid: 8768 ppid:  7642 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit kernel/sched/wait_bit.c:49 [inline]
 out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116
 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251
 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235
 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866
 __ext4_mark_inode_dirty+0x13b/0x6c0 fs/ext4/inode.c:6050
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6087
 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480
 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881
 inode_update_time fs/inode.c:1894 [inline]
 file_update_time+0x3c0/0x440 fs/inode.c:2083
 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6205
 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922
 do_shared_fault mm/memory.c:4328 [inline]
 do_fault mm/memory.c:4396 [inline]
 handle_pte_fault mm/memory.c:4650 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883
 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f1bd7891332
RSP: 002b:00007ffe864e84c0 EFLAGS: 00010202
RAX: 0000000000001008 RBX: 00007f1bd8773720 RCX: 0000000000000000
RDX: 0000001b31323000 RSI: 0000000000000008 RDI: 00007f1bd8773720
RBP: 0000000000000278 R08: 00007f1bd7c2e000 R09: 00007f1bd7c44128
R10: 0000000000000003 R11: 0000000000000002 R12: ffffffff81d6aece
R13: 00007f1bd7c44128 R14: 00000000000000eb R15: fffffffffffff000
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/u4:0/9:
 #0: ffff8880199f2138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88802db740e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418
 #3: ffff88802db76c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
 #4: ffff88802db78990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
 #5: ffff8880748b7020 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668
1 lock held by khungtaskd/27:
 #0: ffffffff8d11efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3944:
 #0: ffff88802c0eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900021ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
3 locks held by syz-executor/4174:
 #0: ffff88807a548f28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807a548f28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88802db78990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
3 locks held by syz.5.1567/8671:
 #0: ffff888076413228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888076413228 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88802db78990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
3 locks held by syz.6.1608/8768:
 #0: ffff888077576328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888077576328 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88802db74558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88802db78990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3540 Comm: syslogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:check_preemption_disabled+0x0/0x110 lib/smp_processor_id.c:13
Code: 00 00 48 c7 c7 20 eb 32 8a e8 2c 01 00 00 65 ff 0d 31 2d 41 76 5b c3 00 00 cc 48 c7 c7 e0 4a 7a 8a 48 c7 c6 20 4b 7a 8a eb 00 <55> 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44
RSP: 0018:ffffc900021d7798 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88807dc98000 RCX: ffffffff815daa54
RDX: dffffc0000000000 RSI: ffffffff8a2b3e00 RDI: ffffffff8a7a4b40
RBP: ffffc900021d7848 R08: ffffffff91015177 R09: 1ffffffff2202a2e
R10: dffffc0000000000 R11: fffffbfff2202a2f R12: ffff88807dc98b38
R13: 0000000000000001 R14: 1ffff1100fb9315d R15: ffff88807dc98b18
FS:  00007f5f99b2cc80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005579ad108660 CR3: 000000002c378000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
 lockdep_hardirqs_on_prepare+0x448/0x7c0 kernel/locking/lockdep.c:4346
 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
 kasan_quarantine_put+0xd4/0x210 mm/kasan/quarantine.c:231
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 skb_free_head net/core/skbuff.c:655 [inline]
 skb_release_data+0x667/0x830 net/core/skbuff.c:677
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb net/core/skbuff.c:756 [inline]
 consume_skb+0xa2/0x100 net/core/skbuff.c:918
 skb_free_datagram+0x25/0xe0 net/core/datagram.c:325
 __unix_dgram_recvmsg+0x9dc/0xd50 net/unix/af_unix.c:2395
 sock_recvmsg_nosec net/socket.c:969 [inline]
 sock_recvmsg net/socket.c:987 [inline]
 sock_read_iter+0x2c2/0x380 net/socket.c:1068
 call_read_iter include/linux/fs.h:2173 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x75e/0xd50 fs/read_write.c:485
 ksys_read+0x153/0x260 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5f99c7c407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffef0a33120 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f5f99b2cc80 RCX: 00007f5f99c7c407
RDX: 00000000000000ff RSI: 000055fd0c142950 RDI: 0000000000000000
RBP: 000055fd0c142910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055fd0c14299a
R13: 0000000000000000 R14: 000055fd0c142950 R15: 000055fcde8ebd98
 </TASK>