BUG: using smp_processor_id() in preemptible [00000000] code: syz-fuzzer/12692 caller is ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711 CPU: 3 PID: 12692 Comm: syz-fuzzer Not tainted 5.7.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 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:3641 do_mkdirat+0x21e/0x280 fs/namei.c:3664 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4b02a0 Code: Bad RIP value. RSP: 002b:000000c0000774b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 000000c00002ea00 RCX: 00000000004b02a0 RDX: 00000000000001c0 RSI: 000000c0000242e0 RDI: ffffffffffffff9c RBP: 000000c000077510 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: ffffffffffffffff R13: 0000000000000018 R14: 0000000000000017 R15: 0000000000000100