Hello, syzbot found the following crash on: HEAD commit: 1b649e0b Merge git://git.kernel.org/pub/scm/linux/kernel/g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15e31ba7e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=27392dd2975fd692 dashboard link: https://syzkaller.appspot.com/bug?extid=313d95e8a7a49263f88d compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13850447e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=119a26f5e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+313d95e8a7a49263f88d@xxxxxxxxxxxxxxxxxxxxxxxxx RSP: 002b:00007ffca409c958 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffca409c970 RCX: 00000000004411c9 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 ================================================================== BUG: KASAN: null-ptr-deref in memset include/linux/string.h:366 [inline] BUG: KASAN: null-ptr-deref in bitmap_zero include/linux/bitmap.h:232 [inline] BUG: KASAN: null-ptr-deref in cpumask_clear include/linux/cpumask.h:406 [inline] BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0xea/0xe90 block/blk-mq.c:2502 Write of size 8 at addr 0000000000000118 by task syz-executor083/7593 CPU: 0 PID: 7593 Comm: syz-executor083 Not tainted 5.6.0-rc7-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+0x188/0x20d lib/dump_stack.c:118 __kasan_report.cold+0x5/0x32 mm/kasan/report.c:510 kasan_report+0xe/0x20 mm/kasan/common.c:641 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x128/0x190 mm/kasan/generic.c:192 memset+0x20/0x40 mm/kasan/common.c:108 memset include/linux/string.h:366 [inline] bitmap_zero include/linux/bitmap.h:232 [inline] cpumask_clear include/linux/cpumask.h:406 [inline] blk_mq_map_swqueue+0xea/0xe90 block/blk-mq.c:2502 blk_mq_init_allocated_queue+0xf21/0x13c0 block/blk-mq.c:2943 blk_mq_init_queue+0x5c/0xa0 block/blk-mq.c:2733 loop_add+0x2cb/0x8a0 drivers/block/loop.c:2022 loop_control_ioctl drivers/block/loop.c:2175 [inline] loop_control_ioctl+0x153/0x340 drivers/block/loop.c:2157 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4411c9 Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffca409c958 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffca409c970 RCX: 00000000004411c9 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 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. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
