Re: [syzbot] [mm?] INFO: task hung in write_cache_pages (2)
From: Dmitry Vyukov
Date: Fri Mar 03 2023 - 00:38:50 EST
On Fri, 3 Mar 2023 at 00:43, Huang, Ying <ying.huang@xxxxxxxxx> wrote:
>
> Yang Shi <shy828301@xxxxxxxxx> writes:
>
> > On Wed, Mar 1, 2023 at 4:36 PM syzbot
> > <syzbot+0adf31ecbba886ab504f@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >>
> >> Hello,
> >>
> >> syzbot found the following issue on:
> >>
> >> HEAD commit: 489fa31ea873 Merge branch 'work.misc' of git://git.kernel...
> >> git tree: upstream
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=1034fef8c80000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=cbfa7a73c540248d
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=0adf31ecbba886ab504f
> >> compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
> >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16dc6960c80000
> >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16f39d50c80000
> >>
> >> Downloadable assets:
> >> disk image: https://storage.googleapis.com/syzbot-assets/8121ff3f8044/disk-489fa31e.raw.xz
> >> vmlinux: https://storage.googleapis.com/syzbot-assets/ba8296ba1bf7/vmlinux-489fa31e.xz
> >> kernel image: https://storage.googleapis.com/syzbot-assets/6459f50e23f3/bzImage-489fa31e.xz
> >> mounted in repro: https://storage.googleapis.com/syzbot-assets/845f6538108c/mount_1.gz
> >>
> >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> >> Reported-by: syzbot+0adf31ecbba886ab504f@xxxxxxxxxxxxxxxxxxxxxxxxx
> >>
> >> INFO: task kworker/u4:0:9 blocked for more than 143 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:kworker/u4:0 state:D stack:21720 pid:9 ppid:2 flags:0x00004000
> >> Workqueue: writeback wb_workfn (flush-7:0)
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> io_schedule+0x8c/0x100 kernel/sched/core.c:8884
> >> folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301
> >> folio_lock include/linux/pagemap.h:952 [inline]
> >> write_cache_pages+0x58f/0x1450 mm/page-writeback.c:2440
> >> mpage_writepages+0x107/0x1d0 fs/mpage.c:653
> >> do_writepages+0x3a6/0x670 mm/page-writeback.c:2551
> >> __writeback_single_inode+0x1c4/0x15e0 fs/fs-writeback.c:1600
> >> writeback_sb_inodes+0x92c/0x1360 fs/fs-writeback.c:1891
> >> __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1962
> >> wb_writeback+0x51c/0x1080 fs/fs-writeback.c:2067
> >> wb_check_background_flush fs/fs-writeback.c:2133 [inline]
> >> wb_do_writeback fs/fs-writeback.c:2221 [inline]
> >> wb_workfn+0xd80/0x1100 fs/fs-writeback.c:2248
> >> process_one_work+0x915/0x13a0 kernel/workqueue.c:2390
> >> worker_thread+0xa63/0x1210 kernel/workqueue.c:2537
> >> kthread+0x270/0x300 kernel/kthread.c:376
> >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
> >> </TASK>
> >> INFO: task kworker/u4:2:41 blocked for more than 143 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:kworker/u4:2 state:D stack:20480 pid:41 ppid:2 flags:0x00004000
> >> Workqueue: writeback wb_workfn (flush-7:5)
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> io_schedule+0x8c/0x100 kernel/sched/core.c:8884
> >> folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301
> >> folio_lock include/linux/pagemap.h:952 [inline]
> >> write_cache_pages+0x58f/0x1450 mm/page-writeback.c:2440
> >> mpage_writepages+0x107/0x1d0 fs/mpage.c:653
> >> do_writepages+0x3a6/0x670 mm/page-writeback.c:2551
> >> __writeback_single_inode+0x1c4/0x15e0 fs/fs-writeback.c:1600
> >> writeback_sb_inodes+0x92c/0x1360 fs/fs-writeback.c:1891
> >> __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1962
> >> wb_writeback+0x51c/0x1080 fs/fs-writeback.c:2067
> >> wb_check_old_data_flush fs/fs-writeback.c:2167 [inline]
> >> wb_do_writeback fs/fs-writeback.c:2220 [inline]
> >> wb_workfn+0xccb/0x1100 fs/fs-writeback.c:2248
> >> process_one_work+0x915/0x13a0 kernel/workqueue.c:2390
> >> worker_thread+0xa63/0x1210 kernel/workqueue.c:2537
> >> kthread+0x270/0x300 kernel/kthread.c:376
> >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
> >> </TASK>
> >> INFO: task kworker/u4:4:75 blocked for more than 144 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:kworker/u4:4 state:D stack:25088 pid:75 ppid:2 flags:0x00004000
> >> Workqueue: writeback wb_workfn (flush-7:1)
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> io_schedule+0x8c/0x100 kernel/sched/core.c:8884
> >> folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301
> >> folio_lock include/linux/pagemap.h:952 [inline]
> >> write_cache_pages+0x58f/0x1450 mm/page-writeback.c:2440
> >> mpage_writepages+0x107/0x1d0 fs/mpage.c:653
> >> do_writepages+0x3a6/0x670 mm/page-writeback.c:2551
> >> __writeback_single_inode+0x1c4/0x15e0 fs/fs-writeback.c:1600
> >> writeback_sb_inodes+0x92c/0x1360 fs/fs-writeback.c:1891
> >> __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1962
> >> wb_writeback+0x51c/0x1080 fs/fs-writeback.c:2067
> >> wb_check_old_data_flush fs/fs-writeback.c:2167 [inline]
> >> wb_do_writeback fs/fs-writeback.c:2220 [inline]
> >> wb_workfn+0xccb/0x1100 fs/fs-writeback.c:2248
> >> process_one_work+0x915/0x13a0 kernel/workqueue.c:2390
> >> worker_thread+0xa63/0x1210 kernel/workqueue.c:2537
> >> kthread+0x270/0x300 kernel/kthread.c:376
> >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
> >> </TASK>
> >> INFO: task syz-executor359:5222 blocked for more than 144 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:syz-executor359 state:D stack:26576 pid:5222 ppid:5113 flags:0x00004004
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6757
> >> rwsem_down_read_slowpath+0x5f4/0x950 kernel/locking/rwsem.c:1086
> >> __down_read_common+0x61/0x2c0 kernel/locking/rwsem.c:1250
> >> mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
> >> RIP: 0033:0x7fd6f371b888
> >> RSP: 002b:00007ffd6fdf2398 EFLAGS: 00010206
> >> RAX: 00007fd6f374ebd0 RBX: 00007fd6f374d1a8 RCX: 0000000000000001
> >> RDX: 00007fd6f3688d30 RSI: 0000000000000000 RDI: 00007fd6f374ebd0
> >> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000010
> >> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> >> R13: 0000000000000001 R14: 00007fd6f37543e0 R15: 0000000000000001
> >> </TASK>
> >> INFO: task syz-executor359:5223 blocked for more than 144 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:syz-executor359 state:D stack:24840 pid:5223 ppid:5113 flags:0x00004004
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> io_schedule+0x8c/0x100 kernel/sched/core.c:8884
> >> folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301
> >> folio_lock include/linux/pagemap.h:952 [inline]
> >> write_cache_pages+0x58f/0x1450 mm/page-writeback.c:2440
> >> mpage_writepages+0x107/0x1d0 fs/mpage.c:653
> >> do_writepages+0x3a6/0x670 mm/page-writeback.c:2551
> >> filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:390
> >> __filemap_fdatawrite_range mm/filemap.c:423 [inline]
> >> file_write_and_wait_range+0x20f/0x300 mm/filemap.c:781
> >> __generic_file_fsync+0x72/0x190 fs/libfs.c:1132
> >> fat_file_fsync+0x7e/0x190 fs/fat/file.c:191
> >> generic_write_sync include/linux/fs.h:2452 [inline]
> >> generic_file_write_iter+0x2a1/0x310 mm/filemap.c:4090
> >> call_write_iter include/linux/fs.h:1851 [inline]
> >> new_sync_write fs/read_write.c:491 [inline]
> >> vfs_write+0x7b2/0xbb0 fs/read_write.c:584
> >> ksys_write+0x1a0/0x2c0 fs/read_write.c:637
> >> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> >> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> >> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >> RIP: 0033:0x7fd6f36ca719
> >> RSP: 002b:00007fd6f36762f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> >> RAX: ffffffffffffffda RBX: 00007fd6f374f7a0 RCX: 00007fd6f36ca719
> >> RDX: 000000000208e24b RSI: 0000000020000080 RDI: 0000000000000004
> >> RBP: 00007fd6f371c604 R08: 0000000000000000 R09: 0000000000000000
> >> R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd6f371c0e0
> >> R13: 0000000020000a80 R14: 0030656c69662f2e R15: 00007fd6f374f7a8
> >> </TASK>
> >> INFO: task syz-executor359:5229 blocked for more than 144 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:syz-executor359 state:D stack:26504 pid:5229 ppid:5113 flags:0x00004004
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> io_schedule+0x8c/0x100 kernel/sched/core.c:8884
> >> folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301
> >> folio_wait_writeback+0xec/0x1f0 mm/page-writeback.c:3127
> >> migrate_folio_unmap mm/migrate.c:1192 [inline]
> >> migrate_pages_batch mm/migrate.c:1685 [inline]
> >> migrate_pages+0x2d50/0x6610 mm/migrate.c:1973
> >
> > The migration has locked the page, but is waiting for writeback. The
> > writeback is waiting for the page lock...
> >
> > I recalled Huge reported the same bug. There is a patch to solve it,
> > but may be not shown in linus's tree yet. And It seems like the
> > reproducer is dirtying some files on loop device and calling mbind at
> > the same time. This does match the reproducer mentioned by Hugh.
>
> Yes. We have fixed a bug report similar. The fix patchset is as
> follows,
>
> https://lore.kernel.org/linux-mm/20230224141145.96814-1-ying.huang@xxxxxxxxx/
>
> It will take some time for it to land in Linus's tree.
Let's tell the bot about the fix so that it reports similar issues in future:
#syz fix: migrate_pages: fix deadlock in batched migration
> Best Regards,
> Huang, Ying
>
> >> do_mbind mm/mempolicy.c:1338 [inline]
> >> kernel_mbind mm/mempolicy.c:1485 [inline]
> >> __do_sys_mbind mm/mempolicy.c:1559 [inline]
> >> __se_sys_mbind+0x75a/0x9c0 mm/mempolicy.c:1555
> >> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> >> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> >> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >> RIP: 0033:0x7fd6f36ca719
> >> RSP: 002b:00007fd6eb3552e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
> >> RAX: ffffffffffffffda RBX: 00007fd6f374f7b0 RCX: 00007fd6f36ca719
> >> RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000000020001000
> >> RBP: 00007fd6f371c604 R08: 0000000000000000 R09: 0000000000000002
> >> R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd6f371c0e0
> >> R13: 0000000020000a80 R14: 0030656c69662f2e R15: 00007fd6f374f7b8
> >> </TASK>
> >> INFO: task syz-executor359:5296 blocked for more than 145 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:syz-executor359 state:D stack:27008 pid:5296 ppid:5112 flags:0x00004004
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6757
> >> rwsem_down_read_slowpath+0x5f4/0x950 kernel/locking/rwsem.c:1086
> >> __down_read_common+0x61/0x2c0 kernel/locking/rwsem.c:1250
> >> mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
> >> RIP: 0033:0x7fd6f371b888
> >> RSP: 002b:00007ffd6fdf2398 EFLAGS: 00010206
> >> RAX: 00007fd6f374ebd0 RBX: 00007fd6f374d1a8 RCX: 0000000000000001
> >> RDX: 00007fd6f3688d30 RSI: 0000000000000000 RDI: 00007fd6f374ebd0
> >> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000010
> >> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> >> R13: 0000000000000001 R14: 00007fd6f37543e0 R15: 0000000000000001
> >> </TASK>
> >> INFO: task syz-executor359:5298 blocked for more than 145 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:syz-executor359 state:D stack:24840 pid:5298 ppid:5112 flags:0x00004004
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> io_schedule+0x8c/0x100 kernel/sched/core.c:8884
> >> folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301
> >> folio_lock include/linux/pagemap.h:952 [inline]
> >> write_cache_pages+0x58f/0x1450 mm/page-writeback.c:2440
> >> mpage_writepages+0x107/0x1d0 fs/mpage.c:653
> >> do_writepages+0x3a6/0x670 mm/page-writeback.c:2551
> >> filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:390
> >> __filemap_fdatawrite_range mm/filemap.c:423 [inline]
> >> file_write_and_wait_range+0x20f/0x300 mm/filemap.c:781
> >> __generic_file_fsync+0x72/0x190 fs/libfs.c:1132
> >> fat_file_fsync+0x7e/0x190 fs/fat/file.c:191
> >> generic_write_sync include/linux/fs.h:2452 [inline]
> >> generic_file_write_iter+0x2a1/0x310 mm/filemap.c:4090
> >> call_write_iter include/linux/fs.h:1851 [inline]
> >> new_sync_write fs/read_write.c:491 [inline]
> >> vfs_write+0x7b2/0xbb0 fs/read_write.c:584
> >> ksys_write+0x1a0/0x2c0 fs/read_write.c:637
> >> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> >> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> >> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >> RIP: 0033:0x7fd6f36ca719
> >> RSP: 002b:00007fd6f36762f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> >> RAX: ffffffffffffffda RBX: 00007fd6f374f7a0 RCX: 00007fd6f36ca719
> >> RDX: 000000000208e24b RSI: 0000000020000080 RDI: 0000000000000004
> >> RBP: 00007fd6f371c604 R08: 0000000000000000 R09: 0000000000000000
> >> R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd6f371c0e0
> >> R13: 0000000020000a80 R14: 0030656c69662f2e R15: 00007fd6f374f7a8
> >> </TASK>
> >> INFO: task syz-executor359:5304 blocked for more than 145 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:syz-executor359 state:D stack:26504 pid:5304 ppid:5112 flags:0x00004004
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> io_schedule+0x8c/0x100 kernel/sched/core.c:8884
> >> folio_wait_bit_common+0x86c/0x12b0 mm/filemap.c:1301
> >> folio_wait_writeback+0xec/0x1f0 mm/page-writeback.c:3127
> >> migrate_folio_unmap mm/migrate.c:1192 [inline]
> >> migrate_pages_batch mm/migrate.c:1685 [inline]
> >> migrate_pages+0x2d50/0x6610 mm/migrate.c:1973
> >> do_mbind mm/mempolicy.c:1338 [inline]
> >> kernel_mbind mm/mempolicy.c:1485 [inline]
> >> __do_sys_mbind mm/mempolicy.c:1559 [inline]
> >> __se_sys_mbind+0x75a/0x9c0 mm/mempolicy.c:1555
> >> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> >> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> >> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >> RIP: 0033:0x7fd6f36ca719
> >> RSP: 002b:00007fd6eb3552e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
> >> RAX: ffffffffffffffda RBX: 00007fd6f374f7b0 RCX: 00007fd6f36ca719
> >> RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000000020001000
> >> RBP: 00007fd6f371c604 R08: 0000000000000000 R09: 0000000000000002
> >> R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd6f371c0e0
> >> R13: 0000000020000a80 R14: 0030656c69662f2e R15: 00007fd6f374f7b8
> >> </TASK>
> >> INFO: task syz-executor359:5460 blocked for more than 146 seconds.
> >> Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> >> task:syz-executor359 state:D stack:26520 pid:5460 ppid:5115 flags:0x00004004
> >> Call Trace:
> >> <TASK>
> >> context_switch kernel/sched/core.c:5304 [inline]
> >> __schedule+0x17d8/0x4990 kernel/sched/core.c:6622
> >> schedule+0xc3/0x180 kernel/sched/core.c:6698
> >> schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6757
> >> rwsem_down_read_slowpath+0x5f4/0x950 kernel/locking/rwsem.c:1086
> >> __down_read_common+0x61/0x2c0 kernel/locking/rwsem.c:1250
> >> mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
> >> RIP: 0033:0x7fd6f371b888
> >> RSP: 002b:00007ffd6fdf2398 EFLAGS: 00010206
> >> RAX: 00007fd6f374ebd0 RBX: 00007fd6f374d1a8 RCX: 0000000000000001
> >> RDX: 00007fd6f3688d30 RSI: 0000000000000000 RDI: 00007fd6f374ebd0
> >> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000010
> >> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> >> R13: 0000000000000001 R14: 00007fd6f37543e0 R15: 0000000000000001
> >> </TASK>
> >> Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings
> >>
> >> Showing all locks held in the system:
> >> 3 locks held by kworker/u4:0/9:
> >> #0: ffff8881451bb938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0
> >> #1: ffffc900000e7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365
> >> #2: ffff88807dfe20e0 (&type->s_umount_key#43){++++}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414
> >> 1 lock held by rcu_tasks_kthre/12:
> >> #0: ffffffff8d127cf0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
> >> 1 lock held by rcu_tasks_trace/13:
> >> #0: ffffffff8d1284f0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
> >> 1 lock held by khungtaskd/28:
> >> #0: ffffffff8d127b20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
> >> 3 locks held by kworker/u4:2/41:
> >> #0: ffff8881451bb938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0
> >> #1: ffffc90000b27d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365
> >> #2: ffff88801d8680e0 (&type->s_umount_key#43){++++}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414
> >> 3 locks held by kworker/u4:4/75:
> >> #0: ffff8881451bb938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0
> >> #1: ffffc900020efd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365
> >> #2: ffff88802c2640e0 (&type->s_umount_key#43){++++}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414
> >> 2 locks held by kworker/1:2/2494:
> >> #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0
> >> #1: ffffc9000a86fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365
> >> 2 locks held by getty/4750:
> >> #0: ffff88814a0e2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:244
> >> #1: ffffc900015802f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2177
> >> 1 lock held by syz-executor359/5222:
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> 2 locks held by syz-executor359/5223:
> >> #0: ffff888021e0f768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x254/0x2f0 fs/file.c:1046
> >> #1: ffff88802c264460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x26d/0xbb0 fs/read_write.c:580
> >> 1 lock held by syz-executor359/5229:
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: do_mbind mm/mempolicy.c:1312 [inline]
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: kernel_mbind mm/mempolicy.c:1485 [inline]
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_mbind mm/mempolicy.c:1559 [inline]
> >> #0: ffff88807d1df698 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_mbind+0x47d/0x9c0 mm/mempolicy.c:1555
> >> 1 lock held by syz-executor359/5296:
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> 2 locks held by syz-executor359/5298:
> >> #0: ffff88807e2b0fe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x254/0x2f0 fs/file.c:1046
> >> #1: ffff88807dfe2460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x26d/0xbb0 fs/read_write.c:580
> >> 1 lock held by syz-executor359/5304:
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: do_mbind mm/mempolicy.c:1312 [inline]
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: kernel_mbind mm/mempolicy.c:1485 [inline]
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_mbind mm/mempolicy.c:1559 [inline]
> >> #0: ffff88802cd0ae98 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_mbind+0x47d/0x9c0 mm/mempolicy.c:1555
> >> 1 lock held by syz-executor359/5460:
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> 2 locks held by syz-executor359/5461:
> >> #0: ffff88801da66ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x254/0x2f0 fs/file.c:1046
> >> #1: ffff888148d0a460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x26d/0xbb0 fs/read_write.c:580
> >> 1 lock held by syz-executor359/5467:
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: do_mbind mm/mempolicy.c:1312 [inline]
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: kernel_mbind mm/mempolicy.c:1485 [inline]
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_mbind mm/mempolicy.c:1559 [inline]
> >> #0: ffff888022485298 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_mbind+0x47d/0x9c0 mm/mempolicy.c:1555
> >> 1 lock held by syz-executor359/5570:
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> 2 locks held by syz-executor359/5571:
> >> #0: ffff88807838a5e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x254/0x2f0 fs/file.c:1046
> >> #1: ffff88801d868460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x26d/0xbb0 fs/read_write.c:580
> >> 1 lock held by syz-executor359/5575:
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: do_mbind mm/mempolicy.c:1312 [inline]
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: kernel_mbind mm/mempolicy.c:1485 [inline]
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_mbind mm/mempolicy.c:1559 [inline]
> >> #0: ffff88807d295298 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_mbind+0x47d/0x9c0 mm/mempolicy.c:1555
> >> 1 lock held by syz-executor359/5572:
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1358 [inline]
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1498 [inline]
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x558/0x8a0 arch/x86/mm/fault.c:1554
> >> 2 locks held by syz-executor359/5573:
> >> #0: ffff888026d84d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x254/0x2f0 fs/file.c:1046
> >> #1: ffff88807b6ac460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x26d/0xbb0 fs/read_write.c:580
> >> 1 lock held by syz-executor359/5576:
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: do_mbind mm/mempolicy.c:1312 [inline]
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: kernel_mbind mm/mempolicy.c:1485 [inline]
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_mbind mm/mempolicy.c:1559 [inline]
> >> #0: ffff88807d1dc098 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_mbind+0x47d/0x9c0 mm/mempolicy.c:1555
> >> 3 locks held by kworker/u4:3/5614:
> >> #0: ffff8881451bb938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0
> >> #1: ffffc90004defd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365
> >> #2: ffff88807b6ac0e0 (&type->s_umount_key#43){++++}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414
> >> 3 locks held by kworker/u4:5/6087:
> >> #0: ffff8881451bb938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77f/0x13a0
> >> #1: ffffc900055b7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c6/0x13a0 kernel/workqueue.c:2365
> >> #2: ffff888148d0a0e0 (&type->s_umount_key#43){++++}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414
> >> 1 lock held by syz-executor359/12461:
> >> #0: ffffffff8d12d1f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline]
> >> #0: ffffffff8d12d1f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:989
> >>
> >> =============================================
> >>
> >> NMI backtrace for cpu 0
> >> CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
> >> Call Trace:
> >> <TASK>
> >> __dump_stack lib/dump_stack.c:88 [inline]
> >> dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
> >> nmi_cpu_backtrace+0x4e5/0x560 lib/nmi_backtrace.c:113
> >> nmi_trigger_cpumask_backtrace+0x1b4/0x410 lib/nmi_backtrace.c:62
> >> trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
> >> check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
> >> watchdog+0x1024/0x1070 kernel/hung_task.c:379
> >> kthread+0x270/0x300 kernel/kthread.c:376
> >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
> >> </TASK>
> >> Sending NMI from CPU 0 to CPUs 1:
> >> NMI backtrace for cpu 1
> >> CPU: 1 PID: 6343 Comm: kworker/u4:9 Not tainted 6.2.0-syzkaller-10827-g489fa31ea873 #0
> >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
> >> Workqueue: events_unbound toggle_allocation_gate
> >> RIP: 0010:rcu_sync_is_idle include/linux/rcu_sync.h:36 [inline]
> >> RIP: 0010:percpu_up_read include/linux/percpu-rwsem.h:105 [inline]
> >> RIP: 0010:cpus_read_unlock+0x5f/0x130 kernel/cpu.c:322
> >> Code: 85 db 74 1b e8 c2 4f 20 00 89 c3 31 ff 89 c6 e8 87 23 39 00 85
> > db 74 5b e8 ce 1f 39 00 eb 05 e8 c7 1f 39 00 8b 1d 41 be a8 0b <31> ff
> > 89 de e8 68 23 39 00 85 db 0f 85 8c 00 00 00 e8 ab 1f 39 00
> >> RSP: 0018:ffffc90005757b70 EFLAGS: 00000293
> >> RAX: ffffffff81538cb2 RBX: 0000000000000000 RCX: ffff888028643a80
> >> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
> >> RBP: ffffc90005757c50 R08: ffffffff81538ca9 R09: fffffbfff1ce8d2e
> >> R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
> >> R13: 1ffff1104779cc03 R14: 0000000000000000 R15: 1ffff92000aeaf70
> >> FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >> CR2: 00007ffd6fdf0bb8 CR3: 000000000cf30000 CR4: 00000000003506e0
> >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> >> Call Trace:
> >> <TASK>
> >> toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:799
> >> process_one_work+0x915/0x13a0 kernel/workqueue.c:2390
> >> worker_thread+0xa63/0x1210 kernel/workqueue.c:2537
> >> kthread+0x270/0x300 kernel/kthread.c:376
> >> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
> >> </TASK>
> >>
> >>
> >> ---
> >> This report is generated by a bot. It may contain errors.
> >> See https://goo.gl/tpsmEJ for more information about syzbot.
> >> syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.
> >>
> >> syzbot will keep track of this issue. See:
> >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >> syzbot can test patches for this issue, for details see:
> >> https://goo.gl/tpsmEJ#testing-patches