Is remount racy? find_entry called with index = 0 find_entry called with index = 0 find_entry called with index = 0 find_entry called with index = 0 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 0xdffffc00000000cf: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000678-0x000000000000067f] CPU: 0 PID: 4519 Comm: syz.4.42 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline] RIP: 0010:txEnd+0xb0/0x520 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 40 ae eb fe 41 bf 78 06 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 21 ae eb fe 49 8b 1f 48 83 c3 30 RSP: 0018:ffffc900037cfb40 EFLAGS: 00010206 RAX: 00000000000000cf RBX: ffffc900024d1020 RCX: 1ffff920006f9f4c RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 00000000ffffffff RBP: ffffc900037cfdb8 R08: ffffffff901d410f R09: 1ffffffff203a821 R10: dffffc0000000000 R11: fffffbfff203a822 R12: 00000000ffffffe2 R13: dffffc0000000000 R14: ffffc900024d1000 R15: 0000000000000678 FS: 00007f045abd06c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f045c9e4f00 CR3: 0000000079c40000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: jfs_mkdir+0x36d/0xad0 fs/jfs/namei.c:293 vfs_mkdir+0x387/0x570 fs/namei.c:4073 do_mkdirat+0x1df/0x5b0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f045c997819 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:00007f045abd0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f045cc11090 RCX: 00007f045c997819 RDX: 00000000000001c0 RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f045ca2dc91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f045cc11128 R14: 00007f045cc11090 R15: 00007ffcfb914738 Modules linked in: ---[ end trace b6ec5424f1999f97 ]--- RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline] RIP: 0010:txEnd+0xb0/0x520 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 40 ae eb fe 41 bf 78 06 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 21 ae eb fe 49 8b 1f 48 83 c3 30 RSP: 0018:ffffc900037cfb40 EFLAGS: 00010206 RAX: 00000000000000cf RBX: ffffc900024d1020 RCX: 1ffff920006f9f4c RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 00000000ffffffff RBP: ffffc900037cfdb8 R08: ffffffff901d410f R09: 1ffffffff203a821 R10: dffffc0000000000 R11: fffffbfff203a822 R12: 00000000ffffffe2 R13: dffffc0000000000 R14: ffffc900024d1000 R15: 0000000000000678 FS: 00007f045abd06c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f045c9e4f00 CR3: 0000000079c40000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- 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 40 ae eb fe call 0xfeebae5a 1a: 41 bf 78 06 00 00 mov $0x678,%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 21 ae eb fe call 0xfeebae5a 39: 49 8b 1f mov (%r15),%rbx 3c: 48 83 c3 30 add $0x30,%rbx