syzbot has found a reproducer for the following issue on: HEAD commit: 9f16d5e6f220 Merge tag 'for-linus' of git://git.kernel.org.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=10a2e778580000 kernel config: https://syzkaller.appspot.com/x/.config?x=54f7b2f59e7640e5 dashboard link: https://syzkaller.appspot.com/bug?extid=08b113332e19a9378dd5 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=147d3ee8580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14dc15c0580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/7562d921dc97/disk-9f16d5e6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8fb84b5dec53/vmlinux-9f16d5e6.xz kernel image: https://storage.googleapis.com/syzbot-assets/cac8b3f180c1/bzImage-9f16d5e6.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/c1fa91bf8bb1/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+08b113332e19a9378dd5@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor130:5858 blocked for more than 143 seconds. Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor130 state:D stack:29072 pid:5858 tgid:5841 ppid:5837 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:853 [inline] do_unlinkat+0x26a/0x830 fs/namei.c:4574 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4633 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ff0002b49 RSP: 002b:00007f8feff98218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f8ff00946b8 RCX: 00007f8ff0002b49 RDX: 00007f8feffdc0f6 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 00007f8ff00946b0 R08: 00007fffff5b63d7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0031656c69662f2e R13: 00007f8ff00570c0 R14: 0030656c69662f2e R15: 0032656c69662f2e </TASK> INFO: task syz-executor130:5854 blocked for more than 144 seconds. Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor130 state:D stack:28440 pid:5854 tgid:5842 ppid:5838 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:853 [inline] do_unlinkat+0x26a/0x830 fs/namei.c:4574 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4633 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ff0002b49 RSP: 002b:00007f8feff98218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f8ff00946b8 RCX: 00007f8ff0002b49 RDX: 00007f8feffdc0f6 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 00007f8ff00946b0 R08: 00007fffff5b63d7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0031656c69662f2e R13: 00007f8ff00570c0 R14: 0030656c69662f2e R15: 0032656c69662f2e </TASK> INFO: task syz-executor130:5855 blocked for more than 145 seconds. Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor130 state:D stack:28912 pid:5855 tgid:5843 ppid:5836 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:853 [inline] do_unlinkat+0x26a/0x830 fs/namei.c:4574 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4633 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ff0002b49 RSP: 002b:00007f8feff98218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f8ff00946b8 RCX: 00007f8ff0002b49 RDX: 00007f8feffdc0f6 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 00007f8ff00946b0 R08: 00007fffff5b63d7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0031656c69662f2e R13: 00007f8ff00570c0 R14: 0030656c69662f2e R15: 0032656c69662f2e </TASK> INFO: task syz-executor130:5856 blocked for more than 146 seconds. Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor130 state:D stack:29072 pid:5856 tgid:5844 ppid:5839 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:853 [inline] do_unlinkat+0x26a/0x830 fs/namei.c:4574 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4633 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ff0002b49 RSP: 002b:00007f8feff98218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f8ff00946b8 RCX: 00007f8ff0002b49 RDX: 00007f8feffdc0f6 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 00007f8ff00946b0 R08: 00007fffff5b63d7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0031656c69662f2e R13: 00007f8ff00570c0 R14: 0030656c69662f2e R15: 0032656c69662f2e </TASK> INFO: task syz-executor130:5857 blocked for more than 147 seconds. Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor130 state:D stack:29072 pid:5857 tgid:5845 ppid:5840 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:853 [inline] do_unlinkat+0x26a/0x830 fs/namei.c:4574 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4633 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ff0002b49 RSP: 002b:00007f8feff98218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f8ff00946b8 RCX: 00007f8ff0002b49 RDX: 00007f8feffdc0f6 RSI: 0000000000000000 RDI: 0000000020000580 RBP: 00007f8ff00946b0 R08: 00007fffff5b63d7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0031656c69662f2e R13: 00007f8ff00570c0 R14: 0030656c69662f2e R15: 0032656c69662f2e </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e93c520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e93c520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e93c520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 1 lock held by kswapd0/88: 2 locks held by getty/5592: #0: ffff88814cf5a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz-executor130/5848: 2 locks held by syz-executor130/5858: #0: ffff88804b276420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88807720c6c0 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff88807720c6c0 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4574 3 locks held by syz-executor130/5851: 2 locks held by syz-executor130/5854: #0: ffff88804bba2420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88807720cc00 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff88807720cc00 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4574 2 locks held by syz-executor130/5847: 2 locks held by syz-executor130/5855: #0: ffff88807d41c420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff8880770886c0 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff8880770886c0 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4574 3 locks held by syz-executor130/5850: 2 locks held by syz-executor130/5856: #0: ffff88804b886420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff888077088180 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff888077088180 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4574 2 locks held by syz-executor130/5849: 2 locks held by syz-executor130/5857: #0: ffff88804b046420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88807720c180 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:853 [inline] #1: ffff88807720c180 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4574 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5847 Comm: syz-executor130 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__find_get_block+0x831/0x1150 fs/buffer.c:1404 Code: 75 74 73 ff e8 90 3c 7b ff fb 48 c7 44 24 40 0e 36 e0 45 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 38 48 c7 04 08 00 00 00 00 <48> c7 44 08 09 00 00 00 00 66 c7 44 08 11 00 00 c6 44 08 13 00 65 RSP: 0018:ffffc90003f6f340 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff920007ede70 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003f6f478 R08: ffffffff8222697d R09: 1ffffd40002f172e R10: dffffc0000000000 R11: fffff940002f172f R12: 0000000000000000 R13: ffffea000178b940 R14: ffffea000178b900 R15: 00000000003186d1 FS: 00007f8feffb96c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561c4fca3600 CR3: 00000000766a6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> __getblk_slow fs/buffer.c:1127 [inline] bdev_getblk+0x18d/0x550 fs/buffer.c:1431 __bread_gfp+0x86/0x400 fs/buffer.c:1485 sb_bread include/linux/buffer_head.h:346 [inline] get_branch+0x2c3/0x6e0 fs/sysv/itree.c:102 get_block+0x180/0x16d0 fs/sysv/itree.c:222 block_read_full_folio+0x418/0xcd0 fs/buffer.c:2396 filemap_read_folio+0x14b/0x630 mm/filemap.c:2366 do_read_cache_folio+0x3f5/0x850 mm/filemap.c:3826 read_mapping_folio include/linux/pagemap.h:1011 [inline] dir_get_folio fs/sysv/dir.c:64 [inline] sysv_find_entry+0x16a/0x4b0 fs/sysv/dir.c:154 sysv_inode_by_name+0x98/0x2a0 fs/sysv/dir.c:370 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38 lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1692 do_renameat2+0x670/0x13f0 fs/namei.c:5165 __do_sys_rename fs/namei.c:5271 [inline] __se_sys_rename fs/namei.c:5269 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5269 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ff0002b49 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8feffb9218 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007f8ff00946a8 RCX: 00007f8ff0002b49 RDX: 00007f8ff0002b49 RSI: 0000000020000080 RDI: 00000000200000c0 RBP: 00007f8ff00946a0 R08: 0000000000000000 R09: 0000000000000000 R10: 00ffffffffffffff R11: 0000000000000246 R12: 0031656c69662f2e R13: 00007f8ff00570c0 R14: 0030656c69662f2e R15: 0032656c69662f2e </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.677 msecs --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.
