Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 122 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:metapage_write_folio+0xa8/0xca0 fs/jfs/jfs_metapage.c:428 Code: e8 4d 52 7f fe 4d 8d 74 24 18 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 e2 bd e1 fe 4d 8b 36 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 c9 bd e1 fe 49 8b 1e 4d 8d 74 24 RSP: 0000:ffffc900039a7780 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffffd40001d2bfe RCX: ffff88801c723c80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900039a7890 R08: ffffea0000e95ff7 R09: 1ffffd40001d2bfe R10: dffffc0000000000 R11: fffff940001d2bff R12: ffffea0000e95fc0 R13: 0000000000000081 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888126e03000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007eff58403000 CR3: 000000006c106000 CR4: 00000000003526f0 Call Trace: metapage_write_one+0x24c/0x450 fs/jfs/jfs_metapage.c:818 release_metapage+0x5b9/0xab0 fs/jfs/jfs_metapage.c:884 txUnlock+0x509/0xdc0 fs/jfs/jfs_txnmgr.c:948 txLazyCommit fs/jfs/jfs_txnmgr.c:2683 [inline] jfs_lazycommit+0x52e/0xa10 fs/jfs/jfs_txnmgr.c:2734 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:metapage_write_folio+0xa8/0xca0 fs/jfs/jfs_metapage.c:428 Code: e8 4d 52 7f fe 4d 8d 74 24 18 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 e2 bd e1 fe 4d 8b 36 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 c9 bd e1 fe 49 8b 1e 4d 8d 74 24 RSP: 0000:ffffc900039a7780 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffffd40001d2bfe RCX: ffff88801c723c80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900039a7890 R08: ffffea0000e95ff7 R09: 1ffffd40001d2bfe R10: dffffc0000000000 R11: fffff940001d2bff R12: ffffea0000e95fc0 R13: 0000000000000081 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888126e03000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007eff58403000 CR3: 000000006c106000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: e8 4d 52 7f fe call 0xfe7f5252 5: 4d 8d 74 24 18 lea 0x18(%r12),%r14 a: 4c 89 f0 mov %r14,%rax d: 48 c1 e8 03 shr $0x3,%rax 11: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) 16: 74 08 je 0x20 18: 4c 89 f7 mov %r14,%rdi 1b: e8 e2 bd e1 fe call 0xfee1be02 20: 4d 8b 36 mov (%r14),%r14 23: 4c 89 f0 mov %r14,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 4c 89 f7 mov %r14,%rdi 34: e8 c9 bd e1 fe call 0xfee1be02 39: 49 8b 1e mov (%r14),%rbx 3c: 4d rex.WRB 3d: 8d .byte 0x8d 3e: 74 24 je 0x64