ERROR: (device loop0): txBegin: read-only filesystem
ERROR: (device loop0): remounting filesystem as read-only
Oops: general protection fault, probably for non-canonical address 0xdffffc00000000c7: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000638-0x000000000000063f]
CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted syzkaller #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
RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline]
RIP: 0010:txEnd+0xb4/0x530 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 5c f1 db fe 41 bf 38 06 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 3d f1 db fe 49 8b 1f 48 83 c3 30
RSP: 0018:ffffc9000e637aa0 EFLAGS: 00010202
RAX: 00000000000000c7 RBX: ffffc90001389020 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff8d996402 RDI: 00000000ffffffff
RBP: ffffc9000e637d80 R08: ffffffff8fa21977 R09: 1ffffffff1f4432e
R10: dffffc0000000000 R11: fffffbfff1f4432f R12: ffff88801fcdbb20
R13: dffffc0000000000 R14: ffffc90001389000 R15: 0000000000000638
FS:  00007f4f43adf6c0(0000) GS:ffff88808d22f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f35827b5000 CR3: 0000000036c54000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 jfs_symlink+0x770/0xe60 fs/jfs/namei.c:1043
 vfs_symlink+0x294/0x2d0 fs/namei.c:5514
 do_symlinkat+0x1f5/0x3c0 fs/namei.c:5541
 __do_sys_symlink fs/namei.c:5567 [inline]
 __se_sys_symlink fs/namei.c:5565 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:5565
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f42b8f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4f43adf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f4f42de6090 RCX: 00007f4f42b8f7c9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000200000000300
RBP: 00007f4f42c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4f42de6128 R14: 00007f4f42de6090 R15: 00007fff8c18bdc8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:JFS_SBI fs/jfs/jfs_incore.h:217 [inline]
RIP: 0010:txEnd+0xb4/0x530 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 5c f1 db fe 41 bf 38 06 00 00 4c 03 3b 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 3d f1 db fe 49 8b 1f 48 83 c3 30
RSP: 0018:ffffc9000e637aa0 EFLAGS: 00010202
RAX: 00000000000000c7 RBX: ffffc90001389020 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffffffff8d996402 RDI: 00000000ffffffff
RBP: ffffc9000e637d80 R08: ffffffff8fa21977 R09: 1ffffffff1f4432e
R10: dffffc0000000000 R11: fffffbfff1f4432f R12: ffff88801fcdbb20
R13: dffffc0000000000 R14: ffffc90001389000 R15: 0000000000000638
FS:  00007f4f43adf6c0(0000) GS:ffff88808d22f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f35827b5000 CR3: 0000000036c54000 CR4: 0000000000352ef0
----------------
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 5c f1 db fe       	call   0xfedbf176
  1a:	41 bf 38 06 00 00    	mov    $0x638,%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 3d f1 db fe       	call   0xfedbf176
  39:	49 8b 1f             	mov    (%r15),%rbx
  3c:	48 83 c3 30          	add    $0x30,%rbx