INFO: task syz-executor:5828 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21368 pid:5828 tgid:5828 ppid:5826 task_flags:0x440100 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x12a0 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6103 __mark_inode_dirty+0x1eb/0xe50 fs/fs-writeback.c:2527 generic_update_time+0xcf/0xf0 fs/inode.c:2064 inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x17d/0x1c0 fs/inode.c:2335 ext4_page_mkwrite+0x35e/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0xb9e/0x58e0 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1ada/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fcd1f477dcf RSP: 002b:00007ffd86876030 EFLAGS: 00010202 RAX: 00007fcd1e450000 RBX: 0000555559c552e0 RCX: 0000000000000003 RDX: 1ffffffff0902773 RSI: 0000555559c5d428 RDI: 0000000000000008 RBP: 00007ffd86876320 R08: 0000555559c5d430 R09: 00000000000004ee R10: 0000000000000001 R11: 00007ffd86876530 R12: 00007ffd86876380 R13: 0000000000000004 R14: 00007ffd868760a0 R15: 00007ffd86876170 INFO: task syz-executor:16949 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24072 pid:16949 tgid:16949 ppid:16937 task_flags:0x440140 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x12a0 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 __ext4_new_inode+0x175c/0x4d30 fs/ext4/ialloc.c:1132 ext4_mkdir+0x283/0xb80 fs/ext4/namei.c:3007 vfs_mkdir+0x590/0x8c0 fs/namei.c:4359 do_mkdirat+0x304/0x3e0 fs/namei.c:4392 __do_sys_mkdirat fs/namei.c:4409 [inline] __se_sys_mkdirat fs/namei.c:4407 [inline] __x64_sys_mkdirat+0x83/0xb0 fs/namei.c:4407 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f927138d1d7 RSP: 002b:00007fffa621d768 EFLAGS: 00000206 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9271410e89 RCX: 00007f927138d1d7 RDX: 00000000000001ff RSI: 00007f9271410e89 RDI: 00000000ffffff9c RBP: 00007f92715b6738 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 INFO: task syz.0.2441:17152 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2441 state:D stack:26488 pid:17152 tgid:17152 ppid:15935 task_flags:0x440040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x12a0 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6103 __mark_inode_dirty+0x1eb/0xe50 fs/fs-writeback.c:2527 generic_update_time+0xcf/0xf0 fs/inode.c:2064 inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x17d/0x1c0 fs/inode.c:2335 ext4_page_mkwrite+0x35e/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0xb9e/0x58e0 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1ada/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f8f9d06eada RSP: 002b:00007ffe8687da20 EFLAGS: 00010212 RAX: 0000001b2ef192f8 RBX: 00007f8f9dee5720 RCX: 0000001b2ef192f0 RDX: 0000001b2e92021c RSI: 0000000000000008 RDI: 00007f8f9dee5720 RBP: ffffffff893a6f4b R08: 00007f8f9d3b61f8 R09: 00007f8f9d3a2000 R10: 00007f8f9bffb008 R11: 0000000000000003 R12: 0000000000000003 R13: 0000000000000001 R14: ffffffff893a6621 R15: 0000000000000001 INFO: task syz.3.2440:17153 blocked for more than 144 seconds. Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.2440 state:D stack:25672 pid:17153 tgid:17153 ppid:5845 task_flags:0x440040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x12a0 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6103 __mark_inode_dirty+0x1eb/0xe50 fs/fs-writeback.c:2527 generic_update_time+0xcf/0xf0 fs/inode.c:2064 inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x17d/0x1c0 fs/inode.c:2335 ext4_page_mkwrite+0x35e/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7efd6cc6f282 RSP: 002b:00007ffee0d5de50 EFLAGS: 00010202 RAX: 0000000000050008 RBX: 00007efd6dae5720 RCX: 0000000000000000 RDX: 0000001b30ed0000 RSI: 0000000000000008 RDI: 00007efd6dae5720 RBP: 0000000000000253 R08: 00007efd6c3ff048 R09: 00007efd6cfa2000 R10: 00007efd6c3ff008 R11: 0000000000000019 R12: ffffffff8a10f36d R13: 00007efd6cfb6038 R14: 0000000000000044 R15: fffffffffffb0000 INFO: task syz.2.2442:17159 blocked for more than 144 seconds. Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2442 state:D stack:25672 pid:17159 tgid:17159 ppid:5847 task_flags:0x440040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x12a0 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6103 __mark_inode_dirty+0x1eb/0xe50 fs/fs-writeback.c:2527 generic_update_time+0xcf/0xf0 fs/inode.c:2064 inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x17d/0x1c0 fs/inode.c:2335 ext4_page_mkwrite+0x35e/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0xb9e/0x58e0 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1ada/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7faefb06eba8 RSP: 002b:00007ffe5267b110 EFLAGS: 00010202 RAX: fffffffffffe110c RBX: 00007faefbee5720 RCX: 0000001b30c01108 RDX: 0000001b30820220 RSI: 0000000000000004 RDI: 00007faefbee5720 RBP: ffffffff815df230 R08: 00007faefb3b62d8 R09: 00007faefb3a2000 R10: 00007faef8bf6008 R11: 0000000000000018 R12: 0000000000000018 R13: 0000000000000000 R14: ffffffff815dfb5a R15: 0000000000000000 INFO: task syz.2.2442:17177 blocked for more than 145 seconds. Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2442 state:D stack:26776 pid:17177 tgid:17159 ppid:5847 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 folio_wait_bit_common+0x3d6/0x9e0 mm/filemap.c:1317 folio_wait_writeback+0x3c/0x90 mm/page-writeback.c:3149 __filemap_fdatawait_range+0x11f/0x200 mm/filemap.c:539 filemap_fdatawait_keep_errors+0x21/0x30 mm/filemap.c:633 wait_sb_inodes fs/fs-writeback.c:2714 [inline] sync_inodes_sb+0x5fa/0xa70 fs/fs-writeback.c:2836 sync_filesystem+0x177/0x290 fs/sync.c:64 fs_bdev_sync+0x2c/0x40 fs/super.c:1435 blkdev_flushbuf block/ioctl.c:433 [inline] blkdev_common_ioctl+0x1742/0x2480 block/ioctl.c:571 blkdev_ioctl+0x1cb/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faefb18e969 RSP: 002b:00007faefbf5f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007faefb3b6160 RCX: 00007faefb18e969 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 000000000000000a RBP: 00007faefb210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faefb3b6160 R15: 00007ffe5267b0d8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 3 locks held by syz-executor/5828: #0: ffff888034a96a88 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e50c518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff888034ed8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 2 locks held by kworker/u9:5/7824: #0: ffff88802607e948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90004b57d18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 2 locks held by getty/11458: #0: ffff88814e0e00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90017bd62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by syz-executor/16949: #0: ffff88814e50c420 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10e/0x4a0 fs/namei.c:4125 #1: ffff88807aa45378 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88807aa45378 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1bb/0x4a0 fs/namei.c:4132 #2: ffff888034ed8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 3 locks held by syz.0.2441/17152: #0: ffff88807e2a0588 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e50c518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff888034ed8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 3 locks held by syz.3.2440/17153: #0: ffff88807cb0cd08 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e50c518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff888034ed8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 3 locks held by syz.2.2442/17159: #0: ffff8880124d3588 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e50c518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff888034ed8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 2 locks held by syz.2.2442/17177: #0: ffff88814e50c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88814e50c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:120 #1: ffff88814e50c948 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2653 [inline] #1: ffff88814e50c948 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x231/0xa70 fs/fs-writeback.c:2836 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 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: 16274 Comm: kworker/u8:4 Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__lock_acquire+0x15a/0x1ba0 kernel/locking/lockdep.c:5169 Code: 10 45 89 e0 0f b7 43 20 4c 89 5b 10 48 89 df 66 81 e2 ff 1f 4c 89 7b 18 66 25 00 e0 09 d0 66 89 43 20 48 8b 84 24 b0 00 00 00 <48> 89 43 08 41 8b 8e d4 0a 00 00 31 c0 65 8b 15 6a c4 0b 12 85 c9 RSP: 0018:ffffc9000c0b7500 EFLAGS: 00000002 RAX: ffffffff816999dd RBX: ffff8880217be590 RCX: 0000000000000007 RDX: 0000000000000007 RSI: ffff8880217be568 RDI: ffff8880217be590 RBP: ffff8880217be4f0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: ffffffff8e3bf440 R12: 0000000000000000 R13: 0000000000000002 R14: ffff8880217bda00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881249ef000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055db24596600 CR3: 000000000e180000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4341 [inline] __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4360 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599 __alloc_skb+0x166/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1340 [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+0x2b1/0xcf0 drivers/net/netdevsim/dev.c:851 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245