Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 0 UID: 0 PID: 8199 Comm: syz-executor Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1690 [inline] RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4031 Code: 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 8a 34 00 00 44 88 33 48 8b 5c 24 10 48 83 c3 18 49 89 df 49 c1 ef 03 <43> 80 3c 2f 00 74 08 48 89 df e8 97 61 49 fe 48 89 5c 24 10 48 8b RSP: 0018:ffffc900040975e0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888027a59020 RBP: ffffc90004097990 R08: ffff888058bd006b R09: 1ffff1100b17a00d R10: dffffc0000000000 R11: ffffed100b17a00e R12: dffffc0000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000003 FS: 000055555f161500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557d1b479470 CR3: 0000000042d08000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2529 sync_filesystem+0x1c8/0x230 fs/sync.c:66 generic_shutdown_super+0x72/0x2d0 fs/super.c:621 kill_anon_super+0x3b/0x70 fs/super.c:1237 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2121 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbf4377f327 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd3fdac0a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007fbf4377f327 RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffd3fdad250 RBP: 00007fbf437f0134 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffd3fdad250 R13: 00007fbf437f0134 R14: 000055555f1614a8 R15: 00007ffd3fdae310 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1690 [inline] RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4031 Code: 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 8a 34 00 00 44 88 33 48 8b 5c 24 10 48 83 c3 18 49 89 df 49 c1 ef 03 <43> 80 3c 2f 00 74 08 48 89 df e8 97 61 49 fe 48 89 5c 24 10 48 8b RSP: 0018:ffffc900040975e0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888027a59020 RBP: ffffc90004097990 R08: ffff888058bd006b R09: 1ffff1100b17a00d R10: dffffc0000000000 R11: ffffed100b17a00e R12: dffffc0000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000003 FS: 000055555f161500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557d1b544160 CR3: 0000000042d08000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 48 89 add %cl,-0x77(%rax) 5: d8 48 c1 fmuls -0x3f(%rax) 8: e8 03 42 0f b6 call 0xb60f4210 d: 04 28 add $0x28,%al f: 84 c0 test %al,%al 11: 0f 85 8a 34 00 00 jne 0x34a1 17: 44 88 33 mov %r14b,(%rbx) 1a: 48 8b 5c 24 10 mov 0x10(%rsp),%rbx 1f: 48 83 c3 18 add $0x18,%rbx 23: 49 89 df mov %rbx,%r15 26: 49 c1 ef 03 shr $0x3,%r15 * 2a: 43 80 3c 2f 00 cmpb $0x0,(%r15,%r13,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 97 61 49 fe call 0xfe4961d0 39: 48 89 5c 24 10 mov %rbx,0x10(%rsp) 3e: 48 rex.W 3f: 8b .byte 0x8b