syzbot

INFO: task syz-executor.4:5227 blocked for more than 143 seconds.
      Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:26864 pid:5227  tgid:5221  ppid:5080   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1781/0x49d0 kernel/sched/core.c:6736
 __schedule_loop kernel/sched/core.c:6813 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6828
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1086 [inline]
 __down_read_common kernel/locking/rwsem.c:1250 [inline]
 __down_read kernel/locking/rwsem.c:1263 [inline]
 down_read+0x705/0xa40 kernel/locking/rwsem.c:1528
 inode_lock_shared include/linux/fs.h:803 [inline]
 open_last_lookups fs/namei.c:3565 [inline]
 path_openat+0x7c4/0x3240 fs/namei.c:3796
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_open fs/open.c:1429 [inline]
 __se_sys_open fs/open.c:1425 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1425
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f4fe6c7de69
RSP: 002b:00007f4fe79af0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f4fe6dac050 RCX: 00007f4fe6c7de69
RDX: 0000000000000140 RSI: 00000000000d4400 RDI: 0000000020000000
RBP: 00007f4fe6cca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f4fe6dac050 R15: 00007ffcfb4e4348
 </TASK>
INFO: task syz-executor.4:5230 blocked for more than 143 seconds.
      Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:27888 pid:5230  tgid:5221  ppid:5080   flags:0x00000006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1781/0x49d0 kernel/sched/core.c:6736
 __schedule_loop kernel/sched/core.c:6813 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6828
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885
 rwsem_down_write_slowpath+0xeeb/0x13b0 kernel/locking/rwsem.c:1178
 __down_write_common+0x1af/0x200 kernel/locking/rwsem.c:1306
 inode_lock include/linux/fs.h:793 [inline]
 open_last_lookups fs/namei.c:3563 [inline]
 path_openat+0x7d3/0x3240 fs/namei.c:3796
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1432
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f4fe6c7de69
RSP: 002b:00007f4fe798e0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4fe6dac120 RCX: 00007f4fe6c7de69
RDX: 000000000000275a RSI: 00000000200000c0 RDI: ffffffffffffff9c
RBP: 00007f4fe6cca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f4fe6dac120 R15: 00007ffcfb4e4348
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
2 locks held by getty/4819:
 #0: ffff88802f8580a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000314b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
5 locks held by syz-executor.4/5222:
1 lock held by syz-executor.4/5227:
 #0: ffff88807679c188 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:803 [inline]
 #0: ffff88807679c188 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: open_last_lookups fs/namei.c:3565 [inline]
 #0: ffff88807679c188 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: path_openat+0x7c4/0x3240 fs/namei.c:3796
2 locks held by syz-executor.4/5230:
 #0: ffff888027a96420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409
 #1: ffff88807679c188 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline]
 #1: ffff88807679c188 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: open_last_lookups fs/namei.c:3563 [inline]
 #1: ffff88807679c188 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: path_openat+0x7d3/0x3240 fs/namei.c:3796

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xfb0/0xff0 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5222 Comm: syz-executor.4 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__sanitizer_cov_trace_pc+0x3c/0x70 kernel/kcov.c:210
Code: 8b 15 e0 db 6e 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 14 16 00 00 00 74 2c 8b 91 f0 15 00 00 83 fa 02 75 21 <48> 8b 91 f8 15 00 00 48 8b 32 48 8d 7e 01 8b 89 f4 15 00 00 48 39
RSP: 0018:ffffc9000479ef70 EFLAGS: 00000246
RAX: ffffffff81408dcc RBX: ffffc9000479efa0 RCX: ffff88802a098000
RDX: 0000000000000002 RSI: 000000000003ffff RDI: ffffc9000479efa0
RBP: ffffc9000479f030 R08: ffffffff8140ade5 R09: ffffffff8140a8df
R10: 0000000000000003 R11: ffff88802a098000 R12: ffff88802a098000
R13: ffffffff8180dfa0 R14: dffffc0000000000 R15: ffffc9000479efa0
FS:  00007f4fe79d06c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6cfd97c038 CR3: 000000001edde000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 unwind_get_return_address+0x1c/0xc0 arch/x86/kernel/unwind_orc.c:365
 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x174/0x340 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 alloc_buffer_head+0x2d/0x2a0 fs/buffer.c:3001
 folio_alloc_buffers+0x2da/0x840 fs/buffer.c:924
 create_empty_buffers+0x3a/0x740 fs/buffer.c:1650
 block_read_full_folio+0x258/0xe10 fs/buffer.c:2365
 filemap_read_folio+0x1a0/0x790 mm/filemap.c:2333
 do_read_cache_folio+0x134/0x820 mm/filemap.c:3703
 do_read_cache_page+0x30/0x200 mm/filemap.c:3769
 read_mapping_page include/linux/pagemap.h:888 [inline]
 dir_get_page fs/sysv/dir.c:64 [inline]
 sysv_find_entry+0x1af/0x410 fs/sysv/dir.c:157
 sysv_inode_by_name+0x98/0x1f0 fs/sysv/dir.c:374
 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38
 lookup_open fs/namei.c:3475 [inline]
 open_last_lookups fs/namei.c:3566 [inline]
 path_openat+0x1033/0x3240 fs/namei.c:3796
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1432
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f4fe6c7de69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007f4fe79d00c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4fe6dabf80 RCX: 00007f4fe6c7de69
RDX: 000000000000275a RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f4fe6cca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f4fe6dabf80 R15: 00007ffcfb4e4348
 </TASK>