syzbot

INFO: task syz.2.19:6136 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:25928 pid:6136  tgid:6136  ppid:6001   task_flags:0x440040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
 filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
 do_sync_mmap_readahead+0x25e/0x7a0 mm/filemap.c:-1
 filemap_fault+0x62c/0x1200 mm/filemap.c:3445
 __do_fault+0x138/0x390 mm/memory.c:5152
 do_shared_fault mm/memory.c:5637 [inline]
 do_fault mm/memory.c:5711 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault+0x1847/0x5440 mm/memory.c:6195
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fc397b56958
RSP: 002b:00007ffe3e313068 EFLAGS: 00010202
RAX: 0000200000000080 RBX: 0000000000000004 RCX: 0030626c6c756e2f
RDX: 000000000000000c RSI: 6c756e2f7665642f RDI: 0000200000000080
RBP: 0000000000000000 R08: 0000001b31320000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 00007fc397db5fac
R13: 00007fc397db5fa0 R14: fffffffffffffffe R15: 0000000000000006
 </TASK>
INFO: task syz.3.20:6137 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.20        state:D stack:25928 pid:6137  tgid:6137  ppid:6014   task_flags:0x440040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
 filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
 do_sync_mmap_readahead+0x25e/0x7a0 mm/filemap.c:-1
 filemap_fault+0x62c/0x1200 mm/filemap.c:3445
 __do_fault+0x138/0x390 mm/memory.c:5152
 do_shared_fault mm/memory.c:5637 [inline]
 do_fault mm/memory.c:5711 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault+0x1847/0x5440 mm/memory.c:6195
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fd18e556958
RSP: 002b:00007ffd174fcfe8 EFLAGS: 00010202
RAX: 0000200000000080 RBX: 0000000000000004 RCX: 0030626c6c756e2f
RDX: 000000000000000c RSI: 6c756e2f7665642f RDI: 0000200000000080
RBP: 0000000000000000 R08: 0000001b33220000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 00007fd18e7b5fac
R13: 00007fd18e7b5fa0 R14: fffffffffffffffe R15: 0000000000000006
 </TASK>
INFO: task syz.4.21:6138 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.21        state:D stack:25928 pid:6138  tgid:6138  ppid:6006   task_flags:0x440040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
 filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
 do_sync_mmap_readahead+0x25e/0x7a0 mm/filemap.c:-1
 filemap_fault+0x62c/0x1200 mm/filemap.c:3445
 __do_fault+0x138/0x390 mm/memory.c:5152
 do_shared_fault mm/memory.c:5637 [inline]
 do_fault mm/memory.c:5711 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault+0x1847/0x5440 mm/memory.c:6195
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fefa9356958
RSP: 002b:00007ffe8091de58 EFLAGS: 00010202
RAX: 0000200000000080 RBX: 0000000000000004 RCX: 0030626c6c756e2f
RDX: 000000000000000c RSI: 6c756e2f7665642f RDI: 0000200000000080
RBP: 0000000000000000 R08: 0000001b33520000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 00007fefa95b5fac
R13: 00007fefa95b5fa0 R14: fffffffffffffffe R15: 0000000000000006
 </TASK>
INFO: task syz.1.18:6139 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18        state:D stack:25928 pid:6139  tgid:6139  ppid:6011   task_flags:0x440040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
 filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
 do_sync_mmap_readahead+0x25e/0x7a0 mm/filemap.c:-1
 filemap_fault+0x62c/0x1200 mm/filemap.c:3445
 __do_fault+0x138/0x390 mm/memory.c:5152
 do_shared_fault mm/memory.c:5637 [inline]
 do_fault mm/memory.c:5711 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault+0x1847/0x5440 mm/memory.c:6195
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fe716556958
RSP: 002b:00007fff74dded18 EFLAGS: 00010202
RAX: 0000200000000080 RBX: 0000000000000004 RCX: 0030626c6c756e2f
RDX: 000000000000000c RSI: 6c756e2f7665642f RDI: 0000200000000080
RBP: 0000000000000000 R08: 0000001b33020000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 00007fe7167b5fac
R13: 00007fe7167b5fa0 R14: fffffffffffffffe R15: 0000000000000006
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/18:
1 lock held by khungtaskd/31:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/1042:
2 locks held by kworker/u8:7/4434:
2 locks held by getty/5622:
 #0: ffff88802fea40a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz.0.17/6134:
 #0: ffff888022d135a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
 #0: ffff888022d135a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:901
 #1: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:924 [inline]
 #1: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: blkdev_fallocate+0x290/0x530 block/fops.c:902
1 lock held by syz.2.19/6136:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.3.20/6137:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.4.21/6138:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.1.18/6139:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.6.23/6282:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.5.22/6284:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.7.24/6285:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.9.26/6286:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.8.25/6287:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.0.27/6375:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.1.28/6380:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.2.29/6395:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.3.30/6396:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.4.31/6397:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.5.32/6499:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.6.33/6516:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.7.34/6529:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.9.36/6535:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.8.35/6536:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.0.37/6618:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.1.38/6639:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.2.39/6643:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.3.40/6646:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.4.41/6647:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.5.42/6740:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.6.43/6772:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.7.44/6785:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.9.46/6786:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
1 lock held by syz.8.45/6787:
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #0: ffff888022d13748 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x318/0xd40 mm/readahead.c:488
3 locks held by syz-executor/6789:
 #0: ffffffff8eca8880 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8eca8880 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8eca8880 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f538a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f538a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f538a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
 #2: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 e7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d f3 86 0e 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: a8e263504cbd8700 RBX: ffffffff819683c8 RCX: a8e263504cbd8700
RDX: 0000000000000001 RSI: ffffffff8d9b7d7a RDI: ffffffff8be33780
RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3
R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa38c30
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d7b40
FS:  0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7adcdefc18 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>