Hello, syzbot found the following crash on: HEAD commit: 770fbb32 Add linux-next specific files for 20200228 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=104fdfa1e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=576314276bce4ad5 dashboard link: https://syzkaller.appspot.com/bug?extid=889cc963ed79ee90f74f compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=176d7f29e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=134c481de00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+889cc963ed79ee90f74f@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000030: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000180-0x0000000000000187] CPU: 0 PID: 9989 Comm: blkid Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__queue_work+0xe8/0x1280 kernel/workqueue.c:1409 Code: c6 00 bf 97 89 4c 89 e7 e8 15 14 48 02 49 8d 86 80 01 00 00 48 89 c2 48 89 44 24 18 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 94 0e 00 00 41 8b 9e 80 01 00 RSP: 0018:ffffc90002457078 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000030 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000040 R08: ffff88809e21a180 R09: fffffbfff190c866 R10: fffffbfff190c865 R11: ffffffff8c86432b R12: ffff8880a677e518 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000040 FS: 00007fe98e0e6740(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000bd7058 CR3: 00000000a3381000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: queue_work_on+0x18b/0x200 kernel/workqueue.c:1515 queue_work include/linux/workqueue.h:507 [inline] loop_queue_work drivers/block/loop.c:984 [inline] loop_queue_rq+0x5ac/0x1050 drivers/block/loop.c:2038 blk_mq_dispatch_rq_list+0x997/0x17f0 block/blk-mq.c:1246 blk_mq_do_dispatch_sched+0x188/0x3f0 block/blk-mq-sched.c:115 blk_mq_sched_dispatch_requests+0x3cd/0x650 block/blk-mq-sched.c:211 __blk_mq_run_hw_queue+0x1b8/0x2c0 block/blk-mq.c:1382 __blk_mq_delay_run_hw_queue+0x522/0x5e0 block/blk-mq.c:1459 blk_mq_run_hw_queue+0x16c/0x2f0 block/blk-mq.c:1512 blk_mq_sched_insert_requests+0x2d4/0x5f0 block/blk-mq-sched.c:444 blk_mq_flush_plug_list+0x452/0x880 block/blk-mq.c:1758 blk_flush_plug_list+0x2ff/0x460 block/blk-core.c:1772 blk_finish_plug block/blk-core.c:1789 [inline] blk_finish_plug+0x50/0x97 block/blk-core.c:1785 read_pages+0x125/0x610 mm/readahead.c:142 ? 0xffffffff81000000 __do_page_cache_readahead+0x47c/0x570 mm/readahead.c:212 force_page_cache_readahead+0x1dc/0x320 mm/readahead.c:243 page_cache_sync_readahead mm/readahead.c:522 [inline] page_cache_sync_readahead+0x4b8/0x520 mm/readahead.c:509 generic_file_buffered_read mm/filemap.c:2029 [inline] generic_file_read_iter+0x1650/0x2a40 mm/filemap.c:2302 blkdev_read_iter+0x11b/0x180 fs/block_dev.c:2039 call_read_iter include/linux/fs.h:1895 [inline] new_sync_read+0x4a2/0x790 fs/read_write.c:414 __vfs_read+0xc9/0x100 fs/read_write.c:427 vfs_read+0x1ea/0x430 fs/read_write.c:461 ksys_read+0x127/0x250 fs/read_write.c:587 do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fe98d9ee310 Code: 73 01 c3 48 8b 0d 28 4b 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d e5 a2 2b 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 6e 8a 01 00 48 89 04 24 RSP: 002b:00007ffd4d1e1df8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe98d9ee310 RDX: 0000000000000400 RSI: 0000000000bd6c58 RDI: 0000000000000003 RBP: 0000000000bd6c30 R08: 0000000000000028 R09: 0000000001680000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000bd6030 R13: 0000000000000400 R14: 0000000000bd6080 R15: 0000000000bd6c48 Modules linked in: ---[ end trace 0e35dd0f272c5c88 ]--- RIP: 0010:__queue_work+0xe8/0x1280 kernel/workqueue.c:1409 Code: c6 00 bf 97 89 4c 89 e7 e8 15 14 48 02 49 8d 86 80 01 00 00 48 89 c2 48 89 44 24 18 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 94 0e 00 00 41 8b 9e 80 01 00 RSP: 0018:ffffc90002457078 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000030 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000040 R08: ffff88809e21a180 R09: fffffbfff190c866 R10: fffffbfff190c865 R11: ffffffff8c86432b R12: ffff8880a677e518 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000040 FS: 00007fe98e0e6740(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000bd7058 CR3: 00000000a3381000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- 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
