syzbot

BUG: using smp_processor_id() in preemptible [00000000] code: systemd-rfkill/6728
caller is ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711
CPU: 0 PID: 6728 Comm: systemd-rfkill Not tainted 5.7.0-next-20200612-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:3647
 do_mkdirat+0x21e/0x280 fs/namei.c:3670
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd9a5f32687
Code: Bad RIP value.
RSP: 002b:00007ffc4fa1c4f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 000055a3596a9985 RCX: 00007fd9a5f32687
RDX: 00007ffc4fa1c3c0 RSI: 00000000000001ed RDI: 000055a3596a9985
RBP: 00007fd9a5f32680 R08: 0000000000000100 R09: 0000000000000000
R10: 000055a3596a9980 R11: 0000000000000246 R12: 00000000000001ed
R13: 00007ffc4fa1c680 R14: 0000000000000000 R15: 0000000000000000