Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 80.088512][ T32] check_preemption_disabled: 6 callbacks suppressed [ 80.088766][ T32] BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u17:1/32 [ 80.113994][ T32] caller is ext4_mb_new_blocks+0xa4d/0x3b70 [ 80.122634][ T32] CPU: 0 PID: 32 Comm: kworker/u17:1 Not tainted 5.7.0-syzkaller #0 [ 80.132550][ T32] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 [ 80.140551][ T32] Workqueue: writeback wb_workfn (flush-8:0) [ 80.140551][ T32] Call Trace: [ 80.160480][ T32] dump_stack+0x18f/0x20d [ 80.160480][ T32] check_preemption_disabled+0x20d/0x220 [ 80.160480][ T32] ext4_mb_new_blocks+0xa4d/0x3b70 [ 80.183951][ T32] ? ext4_find_extent+0x81a/0xad0 [ 80.183951][ T32] ? ext4_ext_search_right+0x2ca/0xb20 [ 80.197171][ T32] ? ext4_inode_to_goal_block+0x2df/0x3f0 [ 80.199946][ T32] ext4_ext_map_blocks+0x201b/0x33e0 [ 80.210344][ T32] ? ext4_ext_release+0x10/0x10 [ 80.219308][ T32] ? down_write_killable+0x170/0x170 [ 80.219308][ T32] ? ext4_es_lookup_extent+0x41d/0xd10 [ 80.219308][ T32] ext4_map_blocks+0x4cb/0x1640 [ 80.237086][ T32] ? ext4_issue_zeroout+0x1e0/0x1e0 [ 80.240189][ T32] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 80.250459][ T32] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 80.259402][ T32] ? ext4_alloc_io_end_vec+0x145/0x1c0 [ 80.259402][ T32] ext4_writepages+0x1a7b/0x33c0 [ 80.259402][ T32] ? __ext4_mark_inode_dirty+0x940/0x940 [ 80.277094][ T32] ? __lock_acquire+0x2224/0x48b0 [ 80.287093][ T32] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 80.287093][ T32] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 80.301416][ T32] ? __ext4_mark_inode_dirty+0x940/0x940 [ 80.309459][ T32] ? do_writepages+0xfa/0x2a0 [ 80.309459][ T32] do_writepages+0xfa/0x2a0 [ 80.319915][ T32] ? page_writeback_cpu_online+0x10/0x10 [ 80.319915][ T32] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 80.319915][ T32] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 80.338983][ T32] __writeback_single_inode+0x12a/0x13d0 [ 80.338983][ T32] ? _raw_spin_unlock+0x24/0x40 [ 80.338983][ T32] ? wbc_attach_and_unlock_inode+0x545/0x9c0 [ 80.361228][ T32] writeback_sb_inodes+0x515/0xdc0 [ 80.377224][ T32] ? __writeback_single_inode+0x13d0/0x13d0 [ 80.389908][ T32] __writeback_inodes_wb+0xc3/0x250 [ 80.389908][ T32] wb_writeback+0x8db/0xd50 [ 80.400328][ T32] ? writeback_inodes_wb.constprop.0+0x1a0/0x1a0 [ 80.400328][ T32] ? _find_next_bit.constprop.0+0x1a3/0x200 [ 80.420553][ T32] ? cpumask_next+0x3c/0x40 [ 80.427508][ T32] ? get_nr_dirty_inodes+0xd6/0x130 [ 80.430129][ T32] wb_workfn+0xab3/0x1090 [ 80.441593][ T32] ? inode_wait_for_writeback+0x30/0x30 [ 80.441593][ T32] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 80.459408][ T32] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 80.459408][ T32] process_one_work+0x965/0x1690 [ 80.459408][ T32] ? lock_release+0x800/0x800 [ 80.477058][ T32] ? pwq_dec_nr_in_flight+0x310/0x310 [ 80.488124][ T32] ? rwlock_bug.part.0+0x90/0x90 [ 80.488124][ T32] worker_thread+0x96/0xe10 [ 80.497456][ T32] ? process_one_work+0x1690/0x1690 [ 80.501472][ T32] kthread+0x3b5/0x4a0 [ 80.509250][ T32] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 80.509250][ T32] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 80.509250][ T32] ret_from_fork+0x1f/0x30 [ 80.535054][ T32] BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u17:1/32 [ 80.547039][ T32] caller is ext4_mb_new_blocks+0xa4d/0x3b70 [ 80.555018][ T32] CPU: 0 PID: 32 Comm: kworker/u17:1 Not tainted 5.7.0-syzkaller #0 [ 80.556977][ T32] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 [ 80.556977][ T32] Workqueue: writeback wb_workfn (flush-8:0) [ 80.556977][ T32] Call Trace: [ 80.556977][ T32] dump_stack+0x18f/0x20d [ 80.556977][ T32] check_preemption_disabled+0x20d/0x220 [ 80.556977][ T32] ext4_mb_new_blocks+0xa4d/0x3b70 [ 80.556977][ T32] ? ext4_find_extent+0x81a/0xad0 [ 80.556977][ T32] ? ext4_ext_search_right+0x2ca/0xb20 [ 80.556977][ T32] ? ext4_inode_to_goal_block+0x2df/0x3f0 [ 80.556977][ T32] ext4_ext_map_blocks+0x201b/0x33e0 [ 80.556977][ T32] ? ext4_ext_release+0x10/0x10 [ 80.556977][ T32] ? down_write_killable+0x170/0x170 [ 80.556977][ T32] ? ext4_es_lookup_extent+0x41d/0xd10 [ 80.556977][ T32] ext4_map_blocks+0x4cb/0x1640 [ 80.556977][ T32] ? ext4_issue_zeroout+0x1e0/0x1e0 [ 80.556977][ T32] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 80.556977][ T32] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 80.556977][ T32] ? ext4_alloc_io_end_vec+0x145/0x1c0 [ 80.556977][ T32] ext4_writepages+0x1a7b/0x33c0 [ 80.556977][ T32] ? __ext4_mark_inode_dirty+0x940/0x940 [ 80.556977][ T32] ? __lock_acquire+0x2224/0x48b0 [ 80.556977][ T32] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 80.556977][ T32] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 80.556977][ T32] ? __ext4_mark_inode_dirty+0x940/0x940 [ 80.556977][ T32] ? do_writepages+0xfa/0x2a0 [ 80.556977][ T32] do_writepages+0xfa/0x2a0 [ 80.556977][ T32] ? page_writeback_cpu_online+0x10/0x10 [ 80.556977][ T32] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 80.556977][ T32] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 80.556977][ T32] __writeback_single_inode+0x12a/0x13d0 [ 80.556977][ T32] ? _raw_spin_unlock+0x24/0x40 [ 80.556977][ T32] ? wbc_attach_and_unlock_inode+0x545/0x9c0 [ 80.556977][ T32] writeback_sb_inodes+0x515/0xdc0 [ 80.556977][ T32] ? __writeback_single_inode+0x13d0/0x13d0 [ 80.556977][ T32] __writeback_inodes_wb+0xc3/0x250 [ 80.556977][ T32] wb_writeback+0x8db/0xd50 [ 80.556977][ T32] ? writeback_inodes_wb.constprop.0+0x1a0/0x1a0 [ 80.556977][ T32] ? _find_next_bit.constprop.0+0x1a3/0x200 [ 80.556977][ T32] ? cpumask_next+0x3c/0x40 [ 80.556977][ T32] ? get_nr_dirty_inodes+0xd6/0x130 [ 80.556977][ T32] wb_workfn+0xab3/0x1090 [ 80.556977][ T32] ? inode_wait_for_writeback+0x30/0x30 [ 80.556977][ T32] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 80.556977][ T32] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 80.556977][ T32] process_one_work+0x965/0x1690 [ 80.556977][ T32] ? lock_release+0x800/0x800 [ 80.556977][ T32] ? pwq_dec_nr_in_flight+0x310/0x310 [ 80.556977][ T32] ? rwlock_bug.part.0+0x90/0x90 [ 80.556977][ T32] worker_thread+0x96/0xe10 [ 80.556977][ T32] ? process_one_work+0x1690/0x1690 [ 80.556977][ T32] kthread+0x3b5/0x4a0 [ 80.556977][ T32] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 80.556977][ T32] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 80.556977][ T32] ret_from_fork+0x1f/0x30