INFO: task syz.3.4:5866 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4 state:D stack:26416 pid:5866 ppid:5762 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 io_schedule+0x80/0xd0 kernel/sched/core.c:9022 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639 dtSplitRoot+0x203/0x16b0 fs/jfs/jfs_dtree.c:1910 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xeec/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_create+0x6a1/0xa40 fs/jfs/namei.c:137 lookup_open fs/namei.c:3496 [inline] open_last_lookups fs/namei.c:3564 [inline] path_openat+0x1277/0x3190 fs/namei.c:3794 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824 do_sys_openat2+0x12c/0x1c0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 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: 0033:0x7f3c9538f749 RSP: 002b:00007f3c9623c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3c955e6270 RCX: 00007f3c9538f749 RDX: 000000000000275a RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f3c95413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c955e6308 R14: 00007f3c955e6270 R15: 00007fff625565b8 INFO: task syz.3.4:5867 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4 state:D stack:27560 pid:5867 ppid:5762 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 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_nested+0x1b1/0x1f0 kernel/locking/rwsem.c:1690 inode_lock_nested include/linux/fs.h:839 [inline] filename_create+0x1f6/0x460 fs/namei.c:3890 do_mkdirat+0xa1/0x440 fs/namei.c:4136 __do_sys_mkdirat fs/namei.c:4159 [inline] __se_sys_mkdirat fs/namei.c:4157 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4157 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: 0033:0x7f3c9538de97 RSP: 002b:00007f3c9621ae68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f3c9621aef0 RCX: 00007f3c9538de97 RDX: 00000000000001ff RSI: 0000200000000000 RDI: 00000000ffffff9c RBP: 00002000000002c0 R08: 0000200000000080 R09: 0000000000000000 R10: 00002000000002c0 R11: 0000000000000246 R12: 0000200000000000 R13: 00007f3c9621aeb0 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.3.4:5864 blocked for more than 147 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4 state:D stack:22928 pid:5864 ppid:5762 flags:0x00004006 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 io_schedule+0x80/0xd0 kernel/sched/core.c:9022 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639 xtSplitPage+0x26b/0x2170 fs/jfs/jfs_xtree.c:974 xtSplitUp+0x328/0x1f30 fs/jfs/jfs_xtree.c:771 xtInsert+0x3ef/0xe00 fs/jfs/jfs_xtree.c:593 extAlloc+0x9fa/0xf30 fs/jfs/jfs_extent.c:145 jfs_get_block+0x347/0xab0 fs/jfs/inode.c:254 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 jfs_write_begin+0x35/0x70 fs/jfs/inode.c:305 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 __kernel_write_iter+0x274/0x670 fs/read_write.c:517 dump_emit_page fs/coredump.c:957 [inline] dump_user_range+0x3f6/0x800 fs/coredump.c:984 elf_core_dump+0x3114/0x36e0 fs/binfmt_elf.c:2184 do_coredump+0x1755/0x2480 fs/coredump.c:833 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f3c9538f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f3c955e6090 RCX: 00007f3c9538f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f3c95413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f3c955e6128 R14: 00007f3c955e6090 R15: 00007fff625565b8 INFO: task syz.0.1:5871 blocked for more than 147 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1 state:D stack:25168 pid:5871 ppid:5768 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 io_schedule+0x80/0xd0 kernel/sched/core.c:9022 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639 ea_write+0x5e3/0xdd0 fs/jfs/xattr.c:256 ea_put fs/jfs/xattr.c:626 [inline] __jfs_setxattr+0x931/0x1150 fs/jfs/xattr.c:792 __jfs_set_acl+0x121/0x1b0 fs/jfs/acl.c:87 jfs_init_acl+0x203/0x3c0 fs/jfs/acl.c:148 jfs_mkdir+0x226/0xa30 fs/jfs/namei.c:236 vfs_mkdir+0x296/0x440 fs/namei.c:4121 do_mkdirat+0x1d4/0x440 fs/namei.c:4144 __do_sys_mkdirat fs/namei.c:4159 [inline] __se_sys_mkdirat fs/namei.c:4157 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4157 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: 0033:0x7f26b2b8de97 RSP: 002b:00007f26b3adde68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f26b3addef0 RCX: 00007f26b2b8de97 RDX: 00000000000001ff RSI: 0000200000000000 RDI: 00000000ffffff9c RBP: 00002000000002c0 R08: 0000200000000080 R09: 0000000000000000 R10: 00002000000002c0 R11: 0000000000000246 R12: 0000200000000000 R13: 00007f26b3addeb0 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.0.1:5885 blocked for more than 148 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1 state:D stack:24104 pid:5885 ppid:5768 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 io_schedule+0x80/0xd0 kernel/sched/core.c:9022 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639 xtSearch+0x15d/0x1cb0 fs/jfs/jfs_xtree.c:255 xtLookup+0x25b/0x7b0 fs/jfs/jfs_xtree.c:152 extHint+0x229/0x570 fs/jfs/jfs_extent.c:215 jfs_get_block+0x302/0xab0 fs/jfs/inode.c:252 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 jfs_write_begin+0x35/0x70 fs/jfs/inode.c:305 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 __kernel_write_iter+0x274/0x670 fs/read_write.c:517 dump_emit_page fs/coredump.c:957 [inline] dump_user_range+0x3f6/0x800 fs/coredump.c:984 elf_core_dump+0x3114/0x36e0 fs/binfmt_elf.c:2184 do_coredump+0x1755/0x2480 fs/coredump.c:833 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f26b2b8f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f26b2de6090 RCX: 00007f26b2b8f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f26b2c13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f26b2de6128 R14: 00007f26b2de6090 R15: 00007ffccdda0138 Showing all locks held in the system: 7 locks held by kworker/u4:0/11: 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 3 locks held by kworker/u4:2/42: #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000b2fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000b2fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 2 locks held by kworker/0:2/786: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900037c7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900037c7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 4 locks held by kworker/u4:6/1296: #0: ffff888141278138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888141278138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90004b0fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90004b0fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff8880225640e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607 #3: ffff88805e323948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108 2 locks held by dhcpcd/5429: #0: ffff888018ec1690 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: netlink_dump+0xcc/0xde0 net/netlink/af_netlink.c:2200 #1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0x71f/0xde0 net/netlink/af_netlink.c:2263 2 locks held by getty/5527: #0: ffff88802d0370a0 (&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 4 locks held by syz.3.4/5866: #0: ffff888022564418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff88805e3233d0 (&type->i_mutex_dir_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff88805e3233d0 (&type->i_mutex_dir_key#9){++++}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline] #1: ffff88805e3233d0 (&type->i_mutex_dir_key#9){++++}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794 #2: ffff88805e323008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_create+0x1f3/0xa40 fs/jfs/namei.c:100 #3: ffff88805e324bc8 (&jfs_ip->commit_mutex/1){+.+.}-{3:3}, at: jfs_create+0x20e/0xa40 fs/jfs/namei.c:101 2 locks held by syz.3.4/5867: #0: ffff888022564418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff88805e3233d0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline] #1: ffff88805e3233d0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: filename_create+0x1f6/0x460 fs/namei.c:3890 4 locks held by syz.3.4/5864: #0: ffff888022564418 (sb_writers#13){.+.+}-{0:0}, at: do_coredump+0x1734/0x2480 fs/coredump.c:832 #1: ffff88805e323d10 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff88805e323d10 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x2e0 mm/filemap.c:4149 #2: ffff88805e3238b8 (&jfs_ip->rdwrlock#2){+.+.}-{3:3}, at: jfs_get_block+0x142/0xab0 fs/jfs/inode.c:219 #3: ffff88805e323948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10f/0xf30 fs/jfs/jfs_extent.c:81 5 locks held by syz.0.1/5871: #0: ffff8880242f0418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff88805e330ed0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline] #1: ffff88805e330ed0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: filename_create+0x1f6/0x460 fs/namei.c:3890 #2: ffff88805e330b08 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_mkdir+0x1f9/0xa30 fs/jfs/namei.c:233 #3: ffff88805e299d88 (&jfs_ip->commit_mutex/1){+.+.}-{3:3}, at: jfs_mkdir+0x214/0xa30 fs/jfs/namei.c:234 #4: ffff88805e299e20 (&jfs_ip->xattr_sem){++++}-{3:3}, at: __jfs_setxattr+0xe2/0x1150 fs/jfs/xattr.c:678 3 locks held by syz.0.1/5885: #0: ffff8880242f0418 (sb_writers#13){.+.+}-{0:0}, at: do_coredump+0x1734/0x2480 fs/coredump.c:832 #1: ffff88805e298590 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff88805e298590 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x2e0 mm/filemap.c:4149 #2: ffff88805e298138 (&jfs_ip->rdwrlock#2){+.+.}-{3:3}, at: jfs_get_block+0x142/0xab0 fs/jfs/inode.c:219 1 lock held by syz-executor/7457: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/7505: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 3 locks held by kworker/u4:14/7551: #0: ffff88802c3a0938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88802c3a0938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900033d7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900033d7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x14e0 net/ipv6/addrconf.c:4158 3 locks held by kworker/u4:23/7574: #0: ffff88801e2fc538 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88801e2fc538 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900034e7d00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900034e7d00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_dfs_channels_update_work+0xb7/0x630 net/wireless/mlme.c:915 ============================================= 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 10/25/2025 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 985 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:unwind_next_frame+0xe15/0x2970 arch/x86/kernel/unwind_orc.c:581 Code: 49 83 c6 10 4c 89 f7 e8 39 28 00 00 48 89 c2 48 89 54 24 08 49 8d 5f 01 48 8b 44 24 48 42 0f b6 04 28 84 c0 0f 85 d2 15 00 00 <48> 89 d8 48 c1 e8 03 48 89 44 24 28 42 0f b6 04 28 84 c0 0f 85 d9 RSP: 0018:ffffc9000425f510 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff8ecc6091 RCX: ffff888022535a00 RDX: ffffc9000425f648 RSI: ffffffff8cb9e760 RDI: 0000000000000005 RBP: ffffc9000425f698 R08: ffff888022535a00 R09: 0000000000000008 R10: 0000000000000009 R11: 0000000000000000 R12: ffffc9000425f648 R13: dffffc0000000000 R14: ffffffff8ecc608d R15: ffffffff8ecc6090 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f36a0fb7198 CR3: 000000000cb30000 CR4: 00000000003506f0 Call Trace: __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] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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 vkms_vblank_simulate: vblank timer overrun