syzbot

INFO: task syz.0.28:5984 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.28        state:D stack:24496 pid:5984  ppid:5916   flags:0x00004000
Call Trace:
 <TASK>
 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+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
 mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 exit_mmap+0x245/0xb50 mm/mmap.c:3310
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x88e/0x23c0 kernel/exit.c:870
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
 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: 0033:0x7f50a178f749
RSP: 002b:00007ffc4a69acb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f50a178f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc4a69ad1c R08: 000000054a69adaf R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000007
R13: 00000000000927c0 R14: 0000000000024a72 R15: 00007ffc4a69ad70
 </TASK>
INFO: task syz.1.43:6049 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.43        state:D stack:24904 pid:6049  ppid:5918   flags:0x00004000
Call Trace:
 <TASK>
 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+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
 mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 exit_mmap+0x245/0xb50 mm/mmap.c:3310
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x88e/0x23c0 kernel/exit.c:870
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
 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: 0033:0x7f564558f749
RSP: 002b:00007ffc97779458 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f564558f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc977794bc R08: 000000059777954f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000005
R13: 00000000000927c0 R14: 0000000000025dd0 R15: 00007ffc97779510
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/28:
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:4/59:
1 lock held by klogd/5148:
2 locks held by getty/5548:
 #0: ffff88802d0410a0 (&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
1 lock held by syz-execprog/5817:
 #0: ffff8880314ec420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
 #0: ffff8880314ec420 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554
1 lock held by syz-executor/5916:
 #0: ffff88807e071e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88807e071e20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5918:
 #0: ffff88807e0701a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88807e0701a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5927:
 #0: ffff88807a0794a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88807a0794a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.0.28/5984:
 #0: ffff888027ec01a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff888027ec01a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.1.43/6049:
 #0: ffff88801bae8b20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88801bae8b20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 59 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_region_inline mm/kasan/generic.c:172 [inline]
RIP: 0010:kasan_check_range+0x29/0x290 mm/kasan/generic.c:187
Code: cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b8 01 00 00 55 41 57 41 56 41 55 41 54 53 4c 8d 04 37 49 39 f8 0f 82 5a 02 00 00 49 89 f9 <49> c1 e9 2f 41 81 f9 ff ff 01 00 0f 82 46 02 00 00 49 89 ff 49 c1
RSP: 0018:ffffc900015a7a08 EFLAGS: 00000212
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816709bc
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e4a8e28
RBP: ffffc900015a7b48 R08: ffffffff8e4a8e30 R09: ffffffff8e4a8e28
R10: dffffc0000000000 R11: fffffbfff1c951c6 R12: 1ffff920002b4f54
R13: ffffffff8cd2fee0 R14: 0000000000000001 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055eb242e8660 CR3: 000000000cb30000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:504 [inline]
 cpu_online include/linux/cpumask.h:1082 [inline]
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0xbc/0x410 kernel/locking/lockdep.c:5725
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
 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
 </TASK>