Hello, syzbot found the following issue on: HEAD commit: 119009db2674 Merge tag 'vfs-6.15-rc3.fixes.2' of git://git.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15c93fe4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=7a7c679f880028f0 dashboard link: https://syzkaller.appspot.com/bug?extid=6af973a3b8dfd2faefdc compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=179aeccc580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=100b5b98580000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-119009db.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1cd1adb50b98/vmlinux-119009db.xz kernel image: https://storage.googleapis.com/syzbot-assets/d1e790c57be7/bzImage-119009db.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6af973a3b8dfd2faefdc@xxxxxxxxxxxxxxxxxxxxxxxxx BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 0 P4D 0 Oops: Oops: 0010 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 12 Comm: kworker/u32:0 Not tainted 6.15.0-rc2-syzkaller-00471-g119009db2674 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: loop8 loop_rootcg_workfn RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0018:ffffc900000f7a38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffff8beceec0 RCX: ffffffff86084265 RDX: 1ffffffff17d9ddd RSI: ffffc900000f7b28 RDI: ffff8880261b3128 RBP: ffff8880261b3128 R08: 0000000000000005 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000002be0 R12: ffffc900000f7b28 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880d69b2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000000e180000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> lo_rw_aio.isra.0+0x9c2/0xd90 drivers/block/loop.c:393 do_req_filebacked drivers/block/loop.c:424 [inline] loop_handle_cmd drivers/block/loop.c:1866 [inline] loop_process_work+0x8a4/0x10d0 drivers/block/loop.c:1901 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0018:ffffc900000f7a38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffff8beceec0 RCX: ffffffff86084265 RDX: 1ffffffff17d9ddd RSI: ffffc900000f7b28 RDI: ffff8880261b3128 RBP: ffff8880261b3128 R08: 0000000000000005 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000002be0 R12: ffffc900000f7b28 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880d69b2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000000e180000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This report 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 issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
