Hello, syzbot found the following crash on: HEAD commit: af30725c Add linux-next specific files for 20200605 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=126f99a6100000 kernel config: https://syzkaller.appspot.com/x/.config?x=579d800cf0c74ef dashboard link: https://syzkaller.appspot.com/bug?extid=f72682b02970a74a7858 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+f72682b02970a74a7858@xxxxxxxxxxxxxxxxxxxxxxxxx BUG: using smp_processor_id() in preemptible [00000000] code: systemd-rfkill/6769 caller is ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711 CPU: 1 PID: 6769 Comm: systemd-rfkill Not tainted 5.7.0-next-20200605-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+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 ext4_getblk+0xad/0x520 fs/ext4/inode.c:833 ext4_bread+0x7c/0x380 fs/ext4/inode.c:883 ext4_append+0x153/0x360 fs/ext4/namei.c:67 ext4_init_new_dir fs/ext4/namei.c:2757 [inline] ext4_mkdir+0x5e0/0xdf0 fs/ext4/namei.c:2802 vfs_mkdir+0x419/0x690 fs/namei.c:3632 do_mkdirat+0x21e/0x280 fs/namei.c:3655 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f6d60012687 Code: Bad RIP value. RSP: 002b:00007ffd286d9ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 000055f82bd8d985 RCX: 00007f6d60012687 RDX: 00007ffd286d9b70 RSI: 00000000000001ed RDI: 000055f82bd8d985 RBP: 00007f6d60012680 R08: 0000000000000100 R09: 0000000000000000 R10: 000055f82bd8d980 R11: 0000000000000246 R12: 00000000000001ed R13: 00007ffd286d9e30 R14: 0000000000000000 R15: 0000000000000000 --- 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.