Hello, syzbot found the following crash on: HEAD commit: 0e21d462 Add linux-next specific files for 20200602 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=13f3dcca100000 kernel config: https://syzkaller.appspot.com/x/.config?x=ecc1aef35f550ee3 dashboard link: https://syzkaller.appspot.com/bug?extid=8ea916061cc749544c8f compiler: gcc (GCC) 9.0.0 20181231 (experimental) IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+8ea916061cc749544c8f@xxxxxxxxxxxxxxxxxxxxxxxxx BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u4:6/6740 caller is ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711 CPU: 1 PID: 6740 Comm: kworker/u4:6 Not tainted 5.7.0-next-20200602-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 check_preemption_disabled+0x20d/0x220 lib/smp_processor_id.c:48 ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711 ext4_ext_map_blocks+0x201b/0x33e0 fs/ext4/extents.c:4244 ext4_map_blocks+0x4cb/0x1640 fs/ext4/inode.c:626 mpage_map_one_extent fs/ext4/inode.c:2377 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2430 [inline] ext4_writepages+0x1ab5/0x3400 fs/ext4/inode.c:2782 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2338 __writeback_single_inode+0x12a/0x13d0 fs/fs-writeback.c:1453 writeback_sb_inodes+0x515/0xdc0 fs/fs-writeback.c:1717 __writeback_inodes_wb+0xc3/0x250 fs/fs-writeback.c:1786 wb_writeback+0x8db/0xd50 fs/fs-writeback.c:1895 wb_check_old_data_flush fs/fs-writeback.c:1997 [inline] wb_do_writeback fs/fs-writeback.c:2050 [inline] wb_workfn+0xab3/0x1090 fs/fs-writeback.c:2079 process_one_work+0x965/0x1690 kernel/workqueue.c:2269 worker_thread+0x96/0xe10 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 --- 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.
