[v6.1] kernel BUG in dbFindLeaf

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 52a953d0934b Linux 6.1.43
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=145d52eda80000
kernel config: https://syzkaller.appspot.com/x/.config?x=dbf2a0c189909afc
dashboard link: https://syzkaller.appspot.com/bug?extid=6cc2c3149f07b4fda043
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1744c6eda80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1079fa0ba80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/175d4c49360c/disk-52a953d0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06e8901f8922/vmlinux-52a953d0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1a4e0f41505a/Image-52a953d0.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/19f37ca8c9b8/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6cc2c3...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
BUG at fs/jfs/jfs_dmap.c:2958 assert(n < 4)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_dmap.c:2958!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4218 Comm: syz-executor324 Not tainted 6.1.43-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : dbFindLeaf+0x3e0/0x3e4 fs/jfs/jfs_dmap.c:2958
lr : dbFindLeaf+0x3e0/0x3e4 fs/jfs/jfs_dmap.c:2958
sp : ffff80001dca6e70
x29: ffff80001dca6e80 x28: 0000000000000012 x27: dfff800000000000
x26: 00000000ffffffff x25: 0000000000000014 x24: ffff800015e3a430
x23: 0000000000000011 x22: 0000000000000003 x21: 0000000000000000
x20: ffff0000c4dba010 x19: ffff80001dca6f00 x18: ffff80001dca63c0
x17: 0000000000000000 x16: ffff800012117bc4 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001
x11: ff80800008345c20 x10: 0000000000000000 x9 : fe681c7f09d5ce00
x8 : fe681c7f09d5ce00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff80001dca6778 x4 : ffff800015982b20 x3 : ffff80000aa7b8ac
x2 : ffff0001b4571cd0 x1 : 0000000100000000 x0 : 000000000000002b
Call trace:
dbFindLeaf+0x3e0/0x3e4 fs/jfs/jfs_dmap.c:2958
dbAllocDmapLev+0xc4/0x410 fs/jfs/jfs_dmap.c:1959
dbAllocCtl+0x104/0x840 fs/jfs/jfs_dmap.c:1815
dbAllocAG+0x208/0xe4c fs/jfs/jfs_dmap.c:1356
dbAlloc+0x520/0xb68 fs/jfs/jfs_dmap.c:880
extBalloc fs/jfs/jfs_extent.c:321 [inline]
extAlloc+0x3f0/0xdd0 fs/jfs/jfs_extent.c:122
jfs_get_block+0x340/0xb98 fs/jfs/inode.c:248
__block_write_begin_int+0x340/0x13b4 fs/buffer.c:1991
__block_write_begin fs/buffer.c:2041 [inline]
block_write_begin+0x98/0x11c fs/buffer.c:2102
jfs_write_begin+0x44/0x88 fs/jfs/inode.c:304
generic_perform_write+0x278/0x55c mm/filemap.c:3754
__generic_file_write_iter+0x168/0x388 mm/filemap.c:3882
generic_file_write_iter+0xb8/0x2b4 mm/filemap.c:3914
do_iter_write+0x534/0x964 fs/read_write.c:861
vfs_writev fs/read_write.c:934 [inline]
do_pwritev+0x1ec/0x334 fs/read_write.c:1031
__do_sys_pwritev2 fs/read_write.c:1090 [inline]
__se_sys_pwritev2 fs/read_write.c:1081 [inline]
__arm64_sys_pwritev2+0xd4/0x108 fs/read_write.c:1081
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
Code: b00461c3 91058063 528171c2 95964402 (d4210000)
---[ end trace 0000000000000000 ]---


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