On Mon, 13 Apr 2020, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: ab6f762f printk: queue wake_up_klogd irq_work only if per-.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17b90b2be00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=23c5a352e32a1944 > dashboard link: https://syzkaller.appspot.com/bug?extid=40b71e145e73f78f81ad > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+40b71e145e73f78f81ad@xxxxxxxxxxxxxxxxxxxxxxxxx > > ======================================================== > WARNING: possible irq lock inversion dependency detected > 5.6.0-syzkaller #0 Not tainted > -------------------------------------------------------- > syz-executor.0/28978 just changed the state of lock: > ffffffff89a5ee98 (shmlock_user_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] > ffffffff89a5ee98 (shmlock_user_lock){+.+.}-{2:2}, at: user_shm_lock+0xab/0x230 mm/mlock.c:855 > but this lock was taken by another, SOFTIRQ-safe lock in the past: > (&xa->xa_lock#4){..-.}-{2:2} > > > and interrupts could create inverse lock ordering between them. > > > other info that might help us debug this: > Chain exists of: > &xa->xa_lock#4 --> &info->lock --> shmlock_user_lock > > Possible interrupt unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(shmlock_user_lock); > local_irq_disable(); > lock(&xa->xa_lock#4); > lock(&info->lock); > <Interrupt> > lock(&xa->xa_lock#4); > > *** DEADLOCK *** > > 1 lock held by syz-executor.0/28978: > #0: ffff88809ab12550 (&ids->rwsem){++++}-{3:3}, at: ipcget_new ipc/util.c:343 [inline] > #0: ffff88809ab12550 (&ids->rwsem){++++}-{3:3}, at: ipcget+0xc6/0xcb0 ipc/util.c:643 > > the shortest dependencies between 2nd lock and 1st lock: > -> (&xa->xa_lock#4){..-.}-{2:2} { > IN-SOFTIRQ-W at: > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 > test_clear_page_writeback+0x1d7/0x11e0 mm/page-writeback.c:2728 > end_page_writeback+0x239/0x520 mm/filemap.c:1317 > end_buffer_async_write+0x442/0x5c0 fs/buffer.c:384 > end_bio_bh_io_sync+0xe2/0x140 fs/buffer.c:3012 > bio_endio+0x473/0x820 block/bio.c:1422 > req_bio_endio block/blk-core.c:245 [inline] > blk_update_request+0x3e1/0xdc0 block/blk-core.c:1472 > scsi_end_request+0x80/0x7b0 drivers/scsi/scsi_lib.c:575 > scsi_io_completion+0x1e7/0x1300 drivers/scsi/scsi_lib.c:959 > scsi_softirq_done+0x31e/0x3b0 drivers/scsi/scsi_lib.c:1454 > blk_done_softirq+0x2db/0x440 block/blk-softirq.c:37 > __do_softirq+0x26c/0x9f7 kernel/softirq.c:292 > invoke_softirq kernel/softirq.c:373 [inline] > irq_exit+0x192/0x1d0 kernel/softirq.c:413 > exiting_irq arch/x86/include/asm/apic.h:546 [inline] > do_IRQ+0xda/0x270 arch/x86/kernel/irq.c:263 > ret_from_intr+0x0/0x2b > arch_local_irq_enable arch/x86/include/asm/paravirt.h:769 [inline] > __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] > _raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199 > do_exit+0x57b/0x2dd0 kernel/exit.c:774 > call_usermodehelper_exec_async+0x507/0x710 kernel/umh.c:125 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > INITIAL USE at: > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] > _raw_spin_lock_irq+0x5b/0x80 kernel/locking/spinlock.c:167 > spin_lock_irq include/linux/spinlock.h:378 [inline] > __add_to_page_cache_locked+0x607/0xe00 mm/filemap.c:855 > add_to_page_cache_lru+0x1aa/0x700 mm/filemap.c:921 > do_read_cache_page+0x9ab/0x1810 mm/filemap.c:2755 > read_mapping_page include/linux/pagemap.h:397 [inline] > read_part_sector+0xf6/0x600 block/partitions/core.c:643 > adfspart_check_ICS+0x9d/0xc80 block/partitions/acorn.c:360 > check_partition block/partitions/core.c:140 [inline] > blk_add_partitions+0x474/0xe50 block/partitions/core.c:571 > bdev_disk_changed+0x1fb/0x380 fs/block_dev.c:1544 > __blkdev_get+0xb15/0x1530 fs/block_dev.c:1647 > blkdev_get+0x41/0x2b0 fs/block_dev.c:1749 > register_disk block/genhd.c:763 [inline] > __device_add_disk+0xa4f/0x1170 block/genhd.c:853 > add_disk include/linux/genhd.h:294 [inline] > brd_init+0x297/0x463 drivers/block/brd.c:533 > do_one_initcall+0x10a/0x7d0 init/main.c:1157 > do_initcall_level init/main.c:1230 [inline] > do_initcalls init/main.c:1246 [inline] > do_basic_setup init/main.c:1266 [inline] > kernel_init_freeable+0x501/0x5ae init/main.c:1450 > kernel_init+0xd/0x1bb init/main.c:1357 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > } > ... key at: [<ffffffff8c681e60>] __key.18009+0x0/0x40 > ... acquired at: > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 > shmem_uncharge+0x24/0x270 mm/shmem.c:341 > __split_huge_page mm/huge_memory.c:2613 [inline] > split_huge_page_to_list+0x274b/0x33b0 mm/huge_memory.c:2886 > split_huge_page include/linux/huge_mm.h:204 [inline] > shmem_punch_compound+0x13e/0x1e0 mm/shmem.c:814 > shmem_undo_range+0x5f1/0x1b80 mm/shmem.c:870 > shmem_truncate_range+0x27/0xa0 mm/shmem.c:980 > shmem_setattr+0x8b6/0xc80 mm/shmem.c:1039 > notify_change+0xb6d/0x1020 fs/attr.c:336 > do_truncate+0x134/0x1f0 fs/open.c:64 > do_sys_ftruncate+0x4a5/0x570 fs/open.c:195 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > > -> (&info->lock){....}-{2:2} { > INITIAL USE at: > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] > _raw_spin_lock_irq+0x5b/0x80 kernel/locking/spinlock.c:167 > spin_lock_irq include/linux/spinlock.h:378 [inline] > shmem_getpage_gfp+0x937/0x2a10 mm/shmem.c:1882 > shmem_getpage mm/shmem.c:154 [inline] > shmem_write_begin+0x102/0x1e0 mm/shmem.c:2483 > generic_perform_write+0x20a/0x4e0 mm/filemap.c:3302 > __generic_file_write_iter+0x24c/0x610 mm/filemap.c:3431 > generic_file_write_iter+0x3f3/0x630 mm/filemap.c:3463 > call_write_iter include/linux/fs.h:1907 [inline] > new_sync_write+0x4a2/0x700 fs/read_write.c:484 > __vfs_write+0xc9/0x100 fs/read_write.c:497 > vfs_write+0x268/0x5d0 fs/read_write.c:559 > ksys_write+0x12d/0x250 fs/read_write.c:612 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > } > ... key at: [<ffffffff8c66eb00>] __key.56434+0x0/0x40 > ... acquired at: > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:353 [inline] > user_shm_lock+0xab/0x230 mm/mlock.c:855 > shmem_lock+0x1dd/0x2d0 mm/shmem.c:2184 > shmctl_do_lock+0x73f/0x8f0 ipc/shm.c:1111 > ksys_shmctl.constprop.0+0x203/0x350 ipc/shm.c:1188 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > > -> (shmlock_user_lock){+.+.}-{2:2} { > HARDIRQ-ON-W at: > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:353 [inline] > user_shm_lock+0xab/0x230 mm/mlock.c:855 > hugetlb_file_setup+0x4e1/0x677 fs/hugetlbfs/inode.c:1416 > newseg+0x460/0xe60 ipc/shm.c:652 > ipcget_new ipc/util.c:344 [inline] > ipcget+0xf0/0xcb0 ipc/util.c:643 > ksys_shmget ipc/shm.c:742 [inline] > __do_sys_shmget ipc/shm.c:747 [inline] > __se_sys_shmget ipc/shm.c:745 [inline] > __x64_sys_shmget+0x139/0x1a0 ipc/shm.c:745 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > SOFTIRQ-ON-W at: > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:353 [inline] > user_shm_lock+0xab/0x230 mm/mlock.c:855 > hugetlb_file_setup+0x4e1/0x677 fs/hugetlbfs/inode.c:1416 > newseg+0x460/0xe60 ipc/shm.c:652 > ipcget_new ipc/util.c:344 [inline] > ipcget+0xf0/0xcb0 ipc/util.c:643 > ksys_shmget ipc/shm.c:742 [inline] > __do_sys_shmget ipc/shm.c:747 [inline] > __se_sys_shmget ipc/shm.c:745 [inline] > __x64_sys_shmget+0x139/0x1a0 ipc/shm.c:745 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > INITIAL USE at: > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:353 [inline] > user_shm_lock+0xab/0x230 mm/mlock.c:855 > shmem_lock+0x1dd/0x2d0 mm/shmem.c:2184 > shmctl_do_lock+0x73f/0x8f0 ipc/shm.c:1111 > ksys_shmctl.constprop.0+0x203/0x350 ipc/shm.c:1188 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > } > ... key at: [<ffffffff89a5ee98>] shmlock_user_lock+0x18/0x5c0 > ... acquired at: > mark_lock_irq kernel/locking/lockdep.c:3585 [inline] > mark_lock+0x624/0xf10 kernel/locking/lockdep.c:3935 > mark_usage kernel/locking/lockdep.c:3852 [inline] > __lock_acquire+0x990/0x4e00 kernel/locking/lockdep.c:4298 > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:353 [inline] > user_shm_lock+0xab/0x230 mm/mlock.c:855 > hugetlb_file_setup+0x4e1/0x677 fs/hugetlbfs/inode.c:1416 > newseg+0x460/0xe60 ipc/shm.c:652 > ipcget_new ipc/util.c:344 [inline] > ipcget+0xf0/0xcb0 ipc/util.c:643 > ksys_shmget ipc/shm.c:742 [inline] > __do_sys_shmget ipc/shm.c:747 [inline] > __se_sys_shmget ipc/shm.c:745 [inline] > __x64_sys_shmget+0x139/0x1a0 ipc/shm.c:745 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > > > stack backtrace: > CPU: 0 PID: 28978 Comm: syz-executor.0 Not tainted 5.6.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x188/0x20d lib/dump_stack.c:118 > print_irq_inversion_bug kernel/locking/lockdep.c:3448 [inline] > check_usage_backwards.cold+0x1d/0x26 kernel/locking/lockdep.c:3499 > mark_lock_irq kernel/locking/lockdep.c:3585 [inline] > mark_lock+0x624/0xf10 kernel/locking/lockdep.c:3935 > mark_usage kernel/locking/lockdep.c:3852 [inline] > __lock_acquire+0x990/0x4e00 kernel/locking/lockdep.c:4298 > lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 > spin_lock include/linux/spinlock.h:353 [inline] > user_shm_lock+0xab/0x230 mm/mlock.c:855 > hugetlb_file_setup+0x4e1/0x677 fs/hugetlbfs/inode.c:1416 > newseg+0x460/0xe60 ipc/shm.c:652 > ipcget_new ipc/util.c:344 [inline] > ipcget+0xf0/0xcb0 ipc/util.c:643 > ksys_shmget ipc/shm.c:742 [inline] > __do_sys_shmget ipc/shm.c:747 [inline] > __se_sys_shmget ipc/shm.c:745 [inline] > __x64_sys_shmget+0x139/0x1a0 ipc/shm.c:745 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > RIP: 0033:0x45c889 > Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f8090c57c78 EFLAGS: 00000246 ORIG_RAX: 000000000000001d > RAX: ffffffffffffffda RBX: 00007f8090c586d4 RCX: 000000000045c889 > RDX: 0000000078000e02 RSI: 0000000000003000 RDI: 0400000000000000 > RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000020ff2000 R11: 0000000000000246 R12: 00000000ffffffff > R13: 0000000000000b5d R14: 00000000004cd951 R15: 000000000076bf0c > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. https://lore.kernel.org/lkml/alpine.LSU.2.11.2004161707410.16322@eggly.anvils/
