INFO: task syz.2.49:6055 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.49 state:D stack:24496 pid:6055 ppid:5924 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574 mmap_write_lock include/linux/mmap_lock.h:108 [inline] exit_mmap+0x245/0xb50 mm/mmap.c:3310 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f48f5f8efc9 RSP: 002b:00007ffc28cef348 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f48f5f8efc9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc28cef3ac R08: 0000000528cef43f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 000000000002c7e7 R15: 00007ffc28cef400 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by udevd/5157: #0: ffffffff8cdd2090 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline] #0: ffffffff8cdd2090 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline] #0: ffffffff8cdd2090 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741 #1: ffff88807d104420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #1: ffff88807d104420 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline] #1: ffff88807d104420 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline] #1: ffff88807d104420 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741 2 locks held by getty/5551: #0: ffff88814c8560a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/5817: #0: ffff888078126a20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff888078126a20 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554 1 lock held by syz-executor/5922: #0: ffff88807c8a6a20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807c8a6a20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/5924: #0: ffff88807c8a73a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807c8a73a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/5923: #0: ffff888023d23aa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff888023d23aa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/5928: #0: ffff888024ab81a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff888024ab81a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.2.49/6055: #0: ffff88807ddda7a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807ddda7a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.0.71/6092: #0: ffff88801b76c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88801b76c420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/6360: #0: ffff88807c8a1e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807c8a1e20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/6365: #0: ffff88807c8a3120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807c8a3120 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/6441: #0: ffff888020bc9e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff888020bc9e20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.3.423/6508: #0: ffff8880786b3120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff8880786b3120 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 2 locks held by syz-executor/6522: #0: ffffffff8cdd2090 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline] #0: ffffffff8cdd2090 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline] #0: ffffffff8cdd2090 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741 #1: ffff8880786b73a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #1: ffff8880786b73a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline] #1: ffff8880786b73a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline] #1: ffff8880786b73a0 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741 1 lock held by udevd/6524: #0: ffff8880786b27a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff8880786b27a0 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x14a/0x3c0 mm/mmap.c:2958 1 lock held by syz-executor/6549: #0: ffff88807685e0a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807685e0a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.8.426/6635: #0: ffff88807e5281a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807e5281a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.9.427/6636: #0: ffff88801786f3a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88801786f3a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5146 Comm: klogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:info_print_prefix+0x73/0x300 kernel/printk/printk.c:1346 Code: 48 c7 44 24 28 bc 97 62 8c 48 c7 44 24 30 10 b2 6a 81 48 8d 4c 24 20 48 c1 e9 03 48 b8 f1 f1 f1 f1 00 04 f3 f3 48 89 4c 24 18 <4a> 89 04 31 e8 44 d8 1a 00 45 85 e4 74 5b e8 3a d8 1a 00 49 8d 7d RSP: 0018:ffffc900032479c0 EFLAGS: 00000a06 RAX: f3f30400f1f1f1f1 RBX: ffffc90003247b00 RCX: 1ffff92000648f3c RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffc90003247c00 RBP: ffffc90003247a70 R08: ffffc90003247b2f R09: 0000000000000000 R10: ffffc90003247b00 R11: fffff52000648f66 R12: 0000000000000001 R13: ffffc90003247c00 R14: dffffc0000000000 R15: 0000000000000001 FS: 00007f51e6421c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fafa8a6c6c8 CR3: 000000002ddd3000 CR4: 00000000003506f0 Call Trace: record_print_text+0x155/0x420 kernel/printk/printk.c:1402 syslog_print+0x36a/0x590 kernel/printk/printk.c:1613 do_syslog+0x576/0x7f0 kernel/printk/printk.c:1732 __do_sys_syslog kernel/printk/printk.c:1824 [inline] __se_sys_syslog kernel/printk/printk.c:1822 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1822 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f51e65eba37 Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007fff6625a618 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f51e678b490 RCX: 00007f51e65eba37 RDX: 00000000000003ff RSI: 00007f51e678b490 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f51e678b490 R13: 00007f51e6768dfe R14: 00007f51e678b531 R15: 00007f51e678b531