================================================================== BUG: KASAN: null-ptr-deref in set_bit include/asm-generic/bitops-instrumented.h:28 [inline] BUG: KASAN: null-ptr-deref in io_wq_cancel_all+0x28/0x2a0 fs/io-wq.c:617 Write of size 8 at addr 0000000000000004 by task syz-executor.5/12247 CPU: 1 PID: 12247 Comm: syz-executor.5 Not tainted 5.4.0-rc5-next-20191029 #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+0x172/0x1f0 lib/dump_stack.c:113 __kasan_report.cold+0x5/0x41 mm/kasan/report.c:510 kasan_report+0x12/0x20 mm/kasan/common.c:634 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 __kasan_check_write+0x14/0x20 mm/kasan/common.c:98 set_bit include/asm-generic/bitops-instrumented.h:28 [inline] io_wq_cancel_all+0x28/0x2a0 fs/io-wq.c:617 io_uring_flush+0x35a/0x4e0 fs/io_uring.c:3936 filp_close+0xbd/0x170 fs/open.c:1174 close_files fs/file.c:388 [inline] put_files_struct fs/file.c:416 [inline] put_files_struct+0x1d7/0x2f0 fs/file.c:413 exit_files+0x83/0xb0 fs/file.c:445 do_exit+0x8d2/0x2e60 kernel/exit.c:812 do_group_exit+0x135/0x360 kernel/exit.c:921 get_signal+0x47c/0x24f0 kernel/signal.c:2734 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459f49 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7b03359cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000075c078 RCX: 0000000000459f49 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075c078 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075c07c R13: 00007ffdeac83d0f R14: 00007f7b0335a9c0 R15: 000000000075c07c ==================================================================