On Tue, Jun 02, 2020 at 05:20:16AM -0700, syzbot wrote: > 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 #syz dup: linux-next test error: BUG: using smp_processor_id() in preemptible [ADDR] code: syz-fuzzer/6792
