INFO: task syz-executor:5898 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:21736 pid:5898 ppid:1 flags:0x00004004 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 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:199 __wait_on_bit+0xac/0x2d0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:76 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1380 gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline] __gfs2_lookup+0x118/0x270 fs/gfs2/inode.c:905 __lookup_slow+0x281/0x3b0 fs/namei.c:1702 lookup_slow+0x53/0x70 fs/namei.c:1719 walk_component+0x2be/0x3f0 fs/namei.c:2010 lookup_last fs/namei.c:2467 [inline] path_lookupat+0x169/0x440 fs/namei.c:2491 filename_lookup+0x1f4/0x510 fs/namei.c:2520 user_path_at_empty+0x42/0x60 fs/namei.c:2917 user_path_at include/linux/namei.h:57 [inline] ksys_umount fs/namespace.c:1921 [inline] __do_sys_umount fs/namespace.c:1929 [inline] __se_sys_umount fs/namespace.c:1927 [inline] __x64_sys_umount+0xf5/0x170 fs/namespace.c:1927 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: 0033:0x7f2b47190a77 RSP: 002b:00007ffeeec912b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f2b47213d7d RCX: 00007f2b47190a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffeeec91370 RBP: 00007ffeeec91370 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffeeec92460 R13: 00007f2b47213d7d R14: 000055555baef4a8 R15: 00007ffeeec94620 Showing all locks held in the system: 1 lock held by khungtaskd/28: #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 getty/5527: #0: ffff88802ce9c0a0 (&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/5898: #0: ffff88805edf3720 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:814 [inline] #0: ffff88805edf3720 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1718 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5124 Comm: klogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x10/0x80 kernel/kcov.c:293 Code: 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d e0 22 7e 7e <65> 8b 15 e1 22 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90003287308 EFLAGS: 00000282 RAX: ffffffff813aa506 RBX: ffffffff81000000 RCX: ffff88807da58000 RDX: 0000000000000000 RSI: ffffffff81000000 RDI: ffffffff81321d67 RBP: ffffc90003287498 R08: ffff88807da58000 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90003287448 R13: dffffc0000000000 R14: ffffc9000328747d R15: ffffffff81321d67 FS: 00007fc793378c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f765ac4295f CR3: 000000002e1b8000 CR4: 00000000003506e0 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:206 [inline] unwind_next_frame+0x1c6/0x2970 arch/x86/kernel/unwind_orc.c:494 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1284 [inline] alloc_skb_with_frags+0xca/0x7c0 net/core/skbuff.c:6332 sock_alloc_send_pskb+0x857/0x990 net/core/sock.c:2821 unix_dgram_sendmsg+0x5a1/0x1720 net/unix/af_unix.c:2001 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 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: 0033:0x7fc7934c8407 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:00007ffcbc693690 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fc793378c80 RCX: 00007fc7934c8407 RDX: 000000000000008b RSI: 00007ffcbc6937d0 RDI: 0000000000000003 RBP: 00007ffcbc693c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffcbc693c18 R13: 00007ffcbc6937d0 R14: 0000000000000070 R15: 00007ffcbc6937d0