syzbot

loop0: detected capacity change from 0 to 32768
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: 6093 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:dbFindLeaf+0x51d/0x520 fs/jfs/jfs_dmap.c:2983
Code: e9 4c ff ff ff e8 c3 26 73 fe 48 c7 c7 60 9f 8a 8b 48 c7 c6 a0 9c 8a 8b ba a7 0b 00 00 48 c7 c1 80 aa 8a 8b e8 e4 03 d6 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:ffffc9000418ebd8 EFLAGS: 00010246
RAX: 000000000000002b RBX: 0000000000000000 RCX: 7cac40101fcaa000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000831d2d R12: 0000000000000004
R13: 0000000000000008 R14: 0000000000000005 R15: 0000000000000155
FS:  00005555878fd500(0000) GS:ffff888126335000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64c6165000 CR3: 000000001ff64000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 dbAllocDmapLev+0x60/0x3c0 fs/jfs/jfs_dmap.c:1969
 dbAllocCtl+0x14a/0x9c0 fs/jfs/jfs_dmap.c:1825
 dbAllocAny fs/jfs/jfs_dmap.c:1532 [inline]
 dbAlloc+0x642/0xba0 fs/jfs/jfs_dmap.c:878
 extBalloc fs/jfs/jfs_extent.c:336 [inline]
 extAlloc+0x57d/0x1020 fs/jfs/jfs_extent.c:127
 jfs_get_block+0x358/0xad0 fs/jfs/inode.c:254
 get_more_blocks fs/direct-io.c:648 [inline]
 do_direct_IO fs/direct-io.c:936 [inline]
 __blockdev_direct_IO+0x1671/0x3330 fs/direct-io.c:1243
 blockdev_direct_IO include/linux/fs.h:3114 [inline]
 jfs_direct_IO+0x11b/0x220 fs/jfs/inode.c:339
 generic_file_direct_write+0x1dc/0x3e0 mm/filemap.c:4253
 __generic_file_write_iter+0x120/0x240 mm/filemap.c:4422
 generic_file_write_iter+0x14b/0x690 mm/filemap.c:4462
 iter_file_splice_write+0x9a6/0x10f0 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x104/0x160 fs/splice.c:1159
 splice_direct_to_actor+0x545/0xc80 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x19b/0x2a0 fs/splice.c:1228
 do_sendfile+0x547/0x7e0 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff47aa3c819
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:00007ffc664ae558 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007ff47acb5fa0 RCX: 00007ff47aa3c819
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007ff47aad2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff47acb5fac R14: 00007ff47acb5fa0 R15: 00007ff47acb5fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dbFindLeaf+0x51d/0x520 fs/jfs/jfs_dmap.c:2983
Code: e9 4c ff ff ff e8 c3 26 73 fe 48 c7 c7 60 9f 8a 8b 48 c7 c6 a0 9c 8a 8b ba a7 0b 00 00 48 c7 c1 80 aa 8a 8b e8 e4 03 d6 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:ffffc9000418ebd8 EFLAGS: 00010246
RAX: 000000000000002b RBX: 0000000000000000 RCX: 7cac40101fcaa000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000831d2d R12: 0000000000000004
R13: 0000000000000008 R14: 0000000000000005 R15: 0000000000000155
FS:  00005555878fd500(0000) GS:ffff888126335000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64c6165000 CR3: 000000001ff64000 CR4: 00000000003526f0