BUG at fs/jfs/jfs_dmap.c:2983 assert(n < 4)
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kernel BUG at fs/jfs/jfs_dmap.c:2983!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 6951 Comm: syz.5.185 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:dbFindLeaf+0x51d/0x520
Code: e9 4c ff ff ff e8 c3 79 74 fe 48 c7 c7 e0 a2 ca 8b 48 c7 c6 20 a0 ca 8b ba a7 0b 00 00 48 c7 c1 00 ae ca 8b e8 24 89 d9 fd 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57
RSP: 0018:ffffc90004946f98 EFLAGS: 00010246
RAX: 000000000000002b RBX: 0000000000000000 RCX: ae44b1f47ad3da00
RDX: ffffc90004e09000 RSI: 000000000000096f RDI: 0000000000000970
RBP: 0000000000000003 R08: ffffc90004946d27 R09: 1ffff92000928da4
R10: dffffc0000000000 R11: fffff52000928da5 R12: 000000000000000a
R13: 0000000000000008 R14: 0000000000000005 R15: 0000000000000155
FS:  00007fc6a3d026c0(0000) GS:ffff88818e326000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd2a1820ff8 CR3: 00000001114e8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 dbAllocDmapLev+0x60/0x3c0
 dbAlloc+0x994/0xba0
 extAlloc+0x57d/0x1020
 jfs_get_block+0x358/0xad0
 __blockdev_direct_IO+0x15d7/0x32f0
 jfs_direct_IO+0x119/0x220
 generic_file_direct_write+0x1db/0x3e0
 __generic_file_write_iter+0x11d/0x230
 generic_file_write_iter+0x14a/0x680
 do_iter_readv_writev+0x619/0x8c0
 vfs_writev+0x33c/0x990
 __se_sys_pwritev2+0x184/0x2a0
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc6a2d9acb9
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:00007fc6a3d02028 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007fc6a3015fa0 RCX: 00007fc6a2d9acb9
RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000004
RBP: 00007fc6a2e08bf7 R08: 0000000000000000 R09: 0000000000000003
R10: 0000000000009c00 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc6a3016038 R14: 00007fc6a3015fa0 R15: 00007ffcf2b12668
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dbFindLeaf+0x51d/0x520
Code: e9 4c ff ff ff e8 c3 79 74 fe 48 c7 c7 e0 a2 ca 8b 48 c7 c6 20 a0 ca 8b ba a7 0b 00 00 48 c7 c1 00 ae ca 8b e8 24 89 d9 fd 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57
RSP: 0018:ffffc90004946f98 EFLAGS: 00010246
RAX: 000000000000002b RBX: 0000000000000000 RCX: ae44b1f47ad3da00
RDX: ffffc90004e09000 RSI: 000000000000096f RDI: 0000000000000970
RBP: 0000000000000003 R08: ffffc90004946d27 R09: 1ffff92000928da4
R10: dffffc0000000000 R11: fffff52000928da5 R12: 000000000000000a
R13: 0000000000000008 R14: 0000000000000005 R15: 0000000000000155
FS:  00007fc6a3d026c0(0000) GS:ffff88818e326000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc698a7fc00 CR3: 00000001114e8000 CR4: 00000000000006f0
