ERROR: (device loop8): remounting filesystem as read-only jfs_dirty_inode called on read-only volume Is remount racy? jfs_dirty_inode called on read-only volume Is remount racy? jfs_dirty_inode called on read-only volume Is remount racy? general protection fault, probably for non-canonical address 0xdffffc00000000c6: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000630-0x0000000000000637] CPU: 0 PID: 6794 Comm: syz.8.128 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline] RIP: 0010:txEnd+0xb4/0x520 fs/jfs/jfs_txnmgr.c:507 Code: 49 8d 5e 20 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 ac 88 d8 fe 41 bf 30 06 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 8d 88 d8 fe 49 8b 1f 48 83 c3 30 RSP: 0018:ffffc9000443f680 EFLAGS: 00010206 RAX: 00000000000000c6 RBX: ffffc90002609020 RCX: 1ffff92000887eb4 RDX: dffffc0000000000 RSI: ffffffff8acac960 RDI: 00000000ffffffff RBP: ffffc9000443f770 R08: ffffffff911c154f R09: 1ffffffff22382a9 R10: dffffc0000000000 R11: fffffbfff22382aa R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc90002609000 R15: 0000000000000630 FS: 00007fef62fc66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f34fe5bd000 CR3: 000000001fb74000 CR4: 00000000003506f0 Call Trace: jfs_truncate_nolock+0x1e5/0x2c0 fs/jfs/inode.c:406 jfs_truncate+0xce/0x140 fs/jfs/inode.c:418 jfs_setattr+0x4f8/0x750 fs/jfs/file.c:122 notify_change+0xb0d/0xe10 fs/attr.c:499 do_truncate+0x1b0/0x240 fs/open.c:66 handle_truncate fs/namei.c:3299 [inline] do_open fs/namei.c:3644 [inline] path_openat+0x2a32/0x3230 fs/namei.c:3797 do_filp_open+0x1f5/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fef6219c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fef62fc6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fef62415fa0 RCX: 00007fef6219c799 RDX: 0000000000101740 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007fef62232c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000179 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef62416038 R14: 00007fef62415fa0 R15: 00007ffe57dfd248 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline] RIP: 0010:txEnd+0xb4/0x520 fs/jfs/jfs_txnmgr.c:507 Code: 49 8d 5e 20 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 ac 88 d8 fe 41 bf 30 06 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 8d 88 d8 fe 49 8b 1f 48 83 c3 30 RSP: 0018:ffffc9000443f680 EFLAGS: 00010206 RAX: 00000000000000c6 RBX: ffffc90002609020 RCX: 1ffff92000887eb4 RDX: dffffc0000000000 RSI: ffffffff8acac960 RDI: 00000000ffffffff RBP: ffffc9000443f770 R08: ffffffff911c154f R09: 1ffffffff22382a9 R10: dffffc0000000000 R11: fffffbfff22382aa R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc90002609000 R15: 0000000000000630 FS: 00007fef62fc66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f34fe5bd000 CR3: 000000001fb74000 CR4: 00000000003506f0 ---------------- Code disassembly (best guess): 0: 49 8d 5e 20 lea 0x20(%r14),%rbx 4: 48 89 d8 mov %rbx,%rax 7: 48 c1 e8 03 shr $0x3,%rax b: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) 10: 74 08 je 0x1a 12: 48 89 df mov %rbx,%rdi 15: e8 ac 88 d8 fe call 0xfed888c6 1a: 41 bf 30 06 00 00 mov $0x630,%r15d 20: 4c 03 3b add (%rbx),%r15 23: 4c 89 f8 mov %r15,%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: 4c 89 ff mov %r15,%rdi 34: e8 8d 88 d8 fe call 0xfed888c6 39: 49 8b 1f mov (%r15),%rbx 3c: 48 83 c3 30 add $0x30,%rbx