Oops: general protection fault, probably for non-canonical address 0xdffffc0000000014: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x00000000000000a0-0x00000000000000a7] CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: loop2 loop_workfn RIP: 0010:file_inode include/linux/fs.h:1353 [inline] RIP: 0010:kiocb_start_write include/linux/fs.h:2756 [inline] RIP: 0010:lo_rw_aio+0xaa9/0xf00 drivers/block/loop.c:401 Code: 89 33 31 ff 8b 5c 24 44 89 de e8 02 66 3d fc 85 db 0f 84 ca 00 00 00 48 8b 44 24 58 48 8d 98 a0 00 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 98 6a a4 fc 4c 89 7c 24 10 48 8b RSP: 0018:ffffc90000127620 EFLAGS: 00010206 RAX: 0000000000000014 RBX: 00000000000000a0 RCX: ffff88801ceedc40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000127790 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900001276e3 R11: fffff52000024ede R12: ffff888026a7a190 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888026a7a1b0 FS: 0000000000000000(0000) GS:ffff88812627c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557e62ca68 CR3: 000000003c7c6000 CR4: 00000000003526f0 Call Trace: do_req_filebacked drivers/block/loop.c:433 [inline] loop_handle_cmd drivers/block/loop.c:1925 [inline] loop_process_work+0x637/0x11b0 drivers/block/loop.c:1960 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:file_inode include/linux/fs.h:1353 [inline] RIP: 0010:kiocb_start_write include/linux/fs.h:2756 [inline] RIP: 0010:lo_rw_aio+0xaa9/0xf00 drivers/block/loop.c:401 Code: 89 33 31 ff 8b 5c 24 44 89 de e8 02 66 3d fc 85 db 0f 84 ca 00 00 00 48 8b 44 24 58 48 8d 98 a0 00 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 98 6a a4 fc 4c 89 7c 24 10 48 8b RSP: 0018:ffffc90000127620 EFLAGS: 00010206 RAX: 0000000000000014 RBX: 00000000000000a0 RCX: ffff88801ceedc40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000127790 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900001276e3 R11: fffff52000024ede R12: ffff888026a7a190 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888026a7a1b0 FS: 0000000000000000(0000) GS:ffff88812627c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557e62ca68 CR3: 0000000011016000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 89 33 mov %esi,(%rbx) 2: 31 ff xor %edi,%edi 4: 8b 5c 24 44 mov 0x44(%rsp),%ebx 8: 89 de mov %ebx,%esi a: e8 02 66 3d fc call 0xfc3d6611 f: 85 db test %ebx,%ebx 11: 0f 84 ca 00 00 00 je 0xe1 17: 48 8b 44 24 58 mov 0x58(%rsp),%rax 1c: 48 8d 98 a0 00 00 00 lea 0xa0(%rax),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 98 6a a4 fc call 0xfca46ad1 39: 4c 89 7c 24 10 mov %r15,0x10(%rsp) 3e: 48 rex.W 3f: 8b .byte 0x8b