ci starts bisection 2025-09-12 18:11:23.511423582 +0000 UTC m=+79765.898171979 bisecting fixing commit since ab75170520d4964f3acf8bb1f91d34cbc650688e building syzkaller on f3558dbf032eab2b77c1cb11b9ce2baffe7838d3 ensuring issue is reproducible on original commit ab75170520d4964f3acf8bb1f91d34cbc650688e testing commit ab75170520d4964f3acf8bb1f91d34cbc650688e gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: bb5325999d6aee045a8afbcadeaadf28e51ecd4780a489f1203b164a0789729f all runs: crashed: INFO: task hung in iterate_supers representative crash: INFO: task hung in iterate_supers, types: [HANG] check whether we can drop unnecessary instrumentation disabling configs for [kasan locking atomic_sleep memleak ubsan bug_or_warning], they are not needed testing commit ab75170520d4964f3acf8bb1f91d34cbc650688e gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 0e18c168222aeff0f46bd45b38ddef0e8ed41ec3a9051406aafb3228a0199a6b all runs: crashed: INFO: task hung in iterate_supers representative crash: INFO: task hung in iterate_supers, types: [HANG] the bug reproduces without the instrumentation disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed kconfig minimization: base=4093 full=8243 leaves diff=2142 split chunks (needed=false): <2142> split chunk #0 of len 2142 into 5 parts testing without sub-chunk 1/5 disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit ab75170520d4964f3acf8bb1f91d34cbc650688e gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 5d27a221d7acd1a3c6e1baa76b1c17ccd846d128ec0ce3b2ab21249a29db877c all runs: crashed: INFO: task hung in iterate_supers representative crash: INFO: task hung in iterate_supers, types: [HANG] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit ab75170520d4964f3acf8bb1f91d34cbc650688e gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: d4a9546322ebdee0b6a745059404b7f1c2d9e3ed7bae544b51f699d37cf07dc4 all runs: crashed: INFO: task hung in iterate_supers representative crash: INFO: task hung in iterate_supers, types: [HANG] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit ab75170520d4964f3acf8bb1f91d34cbc650688e gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 8a54eb48d57a510febc237e5e2742357068500617b098172509a92afb4569783 all runs: crashed: INFO: task hung in iterate_supers representative crash: INFO: task hung in iterate_supers, types: [HANG] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [kasan locking atomic_sleep memleak ubsan bug_or_warning], they are not needed testing commit ab75170520d4964f3acf8bb1f91d34cbc650688e gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 924a03e421ea74b4a734e590cca202923ce2694d5ba2cdef632b35c5673f23ed all runs: crashed: INFO: task hung in iterate_supers representative crash: INFO: task hung in iterate_supers, types: [HANG] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit ab75170520d4964f3acf8bb1f91d34cbc650688e gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 61d6b6199e76bdeeec2d6d320ab45709106f738c1a7c9f02ff44dba971079743 all runs: crashed: INFO: task hung in iterate_supers representative crash: INFO: task hung in iterate_supers, types: [HANG] the chunk can be dropped disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing current HEAD 22f20375f5b71f30c0d6896583b93b6e4bba7279 testing commit 22f20375f5b71f30c0d6896583b93b6e4bba7279 gcc compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 52617b448fbccdbca8d3c42cdb46bf5cbe5c76bdde886f70cb06f349d619e585 all runs: crashed: INFO: task hung in __iterate_supers representative crash: INFO: task hung in __iterate_supers, types: [HANG] crash still not fixed/happens on the oldest tested release revisions tested: 8, total time: 2h36m36.13724385s (build: 1h36m14.440328759s, test: 48m23.310604079s) crash still not fixed or there were kernel test errors commit msg: Merge tag 'pci-v6.17-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci crash: INFO: task hung in __iterate_supers INFO: task syz.2.18:2406 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.18 state:D stack:14288 pid:2406 tgid:2401 ppid:1915 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x5a2/0xd10 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x25/0x110 kernel/sched/core.c:7058 super_lock+0xcd/0x150 fs/super.c:115 __iterate_supers+0xd0/0x190 fs/super.c:923 ksys_sync+0x3e/0xa0 fs/sync.c:102 __do_sys_sync+0x9/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6d/0x2f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fed49b35d29 RSP: 002b:00007fed495a7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fed49d25fa0 RCX: 00007fed49b35d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fed49d25fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fed49d25fa0 R15: 00007ffd6347b6b8 INFO: task syz.7.16:4156 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.16 state:D stack:14704 pid:4156 tgid:4155 ppid:2396 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x5a2/0xd10 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x25/0x110 kernel/sched/core.c:7058 super_lock+0xcd/0x150 fs/super.c:115 __iterate_supers+0xd0/0x190 fs/super.c:923 ksys_sync+0x3e/0xa0 fs/sync.c:102 __do_sys_sync+0x9/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6d/0x2f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f758d9e5d29 RSP: 002b:00007f758d45f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f758dbd5fa0 RCX: 00007f758d9e5d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f758dbd5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f758dbd5fa0 R15: 00007ffd5c137588 INFO: task syz.3.19:4187 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.19 state:D stack:14288 pid:4187 tgid:4186 ppid:2404 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x5a2/0xd10 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x25/0x110 kernel/sched/core.c:7058 super_lock+0xcd/0x150 fs/super.c:115 __iterate_supers+0xd0/0x190 fs/super.c:923 ksys_sync+0x3e/0xa0 fs/sync.c:102 __do_sys_sync+0x9/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6d/0x2f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7095595d29 RSP: 002b:00007f7095007038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f7095785fa0 RCX: 00007f7095595d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f7095785fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f7095785fa0 R15: 00007ffde1754098 INFO: task syz.1.17:4202 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.17 state:D stack:14704 pid:4202 tgid:4201 ppid:2400 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x5a2/0xd10 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x25/0x110 kernel/sched/core.c:7058 super_lock+0xcd/0x150 fs/super.c:115 __iterate_supers+0xd0/0x190 fs/super.c:923 ksys_sync+0x3e/0xa0 fs/sync.c:102 __do_sys_sync+0x9/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6d/0x2f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f976bf85d29 RSP: 002b:00007f976b9f7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f976c175fa0 RCX: 00007f976bf85d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f976c175fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f976c175fa0 R15: 00007ffc0d4ce168 INFO: task syz.5.20:4207 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.20 state:D stack:14480 pid:4207 tgid:4206 ppid:2405 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x5a2/0xd10 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x25/0x110 kernel/sched/core.c:7058 super_lock+0xcd/0x150 fs/super.c:115 __iterate_supers+0xd0/0x190 fs/super.c:923 ksys_sync+0x3e/0xa0 fs/sync.c:102 __do_sys_sync+0x9/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6d/0x2f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae75a35d29 RSP: 002b:00007fae754af038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fae75c25fa0 RCX: 00007fae75a35d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fae75c25fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fae75c25fa0 R15: 00007fffe0a01678 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff82981c20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff82981c20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff82981c20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x36/0x120 kernel/locking/lockdep.c:6775 2 locks held by getty/851: #0: ffff8881072b40a0 (&tty->ldisc_sem){....}-{0:0}, at: tty_ldisc_ref_wait+0x23/0x60 drivers/tty/tty_ldisc.c:243 #1: ffffc90001d372f0 (&ldata->atomic_read_lock){....}-{3:3}, at: n_tty_read+0x17a/0x660 drivers/tty/n_tty.c:2222 1 lock held by syz.2.18/2429: #0: ffff888106e9f0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.7.16/4181: #0: ffff888105ae60e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.3.19/4208: #0: ffff888107ec40e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.1.17/4209: #0: ffff88810ff7c0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.5.20/4210: #0: ffff8881116390e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.8.21/4664: #0: ffff88811865c0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.4.23/6443: #0: ffff8881183d70e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.0.24/6469: #0: ffff88811848b0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.6.25/6476: #0: ffff88811839a0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.9.22/6477: #0: ffff88811848f0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.2.26/6931: #0: ffff8881103b20e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.3.29/8733: #0: ffff88810435a0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.1.28/8735: #0: ffff8881184750e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.7.27/8745: #0: ffff8881103f20e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.5.30/8746: #0: ffff8881103f50e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.8.31/9200: #0: ffff88810ff6d0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.9.32/10989: #0: ffff8881186270e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.6.35/11009: #0: ffff88810df3c0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.0.34/11014: #0: ffff8881185ee0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.4.33/11015: #0: ffff8881183af0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.2.36/11469: #0: ffff8881183ba0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.5.40/13232: #0: ffff88810f3d60e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.3.39/13281: #0: ffff88810c7bd0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.1.38/13282: #0: ffff88810b7de0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.7.37/13283: #0: ffff88810f3cc0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.8.41/13737: #0: ffff88810bf2b0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.4.43/15500: #0: ffff88810cba30e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.6.45/15548: #0: ffff88810b7a20e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.9.42/15550: #0: ffff88810bf2e0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.0.44/15551: #0: ffff88810bf780e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.2.46/16004: #0: ffff88810ef140e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.5.50/17928: #0: ffff8881204ff0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.1.48/17933: #0: ffff8881097800e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.7.47/17942: #0: ffff8881204ef0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.3.49/17946: #0: ffff8881097860e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.8.51/18270: #0: ffff8881186340e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.9.52/20224: #0: ffff88811875f0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.0.54/20240: #0: ffff888109bea0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.4.53/20296: #0: ffff888109bee0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.2.56/20537: #0: ffff8881187ad0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.6.55/20538: #0: ffff88810a71a0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.5.59/22794: #0: ffff88810db1e0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.8.60/22805: #0: ffff8881205af0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.1.58/22804: #0: ffff8881205aa0e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.3.61/22806: #0: ffff88810c3a80e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 1 lock held by syz.7.57/22807: #0: ffff88810cf430e0 (&type->s_umount_key#54/1){....}-{3:3}, at: alloc_super+0xe6/0x3c0 fs/super.c:345 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x5a/0x90 lib/dump_stack.c:120 nmi_cpu_backtrace+0xd4/0x110 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0xd5/0x140 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0x5f3/0x630 kernel/hung_task.c:491 kthread+0x107/0x200 kernel/kthread.c:463 ret_from_fork+0x192/0x1b0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 21 66 00 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a5 d7 10 00 fb f4 0c 1d 01 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff82803e80 EFLAGS: 000002c2 RAX: 00000000000943ac RBX: ffffffff82824900 RCX: 000000336c482700 RDX: ffff888237c24fe8 RSI: ffffffff82542cfa RDI: ffffffff8251270e RBP: 0000000000000000 R08: 0000000000080000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff82824050 R15: 000000000008b000 FS: 0000000000000000(0000) GS:ffff8882b49d2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f920224 CR3: 000000010bf43000 CR4: 00000000003506f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x48/0x140 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1d4/0x230 kernel/sched/idle.c:330 cpu_startup_entry+0x24/0x30 kernel/sched/idle.c:428 rest_init+0xed/0xf0 init/main.c:744 start_kernel+0x5ea/0x690 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x103/0x120 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148