[v5.15] UBSAN: array-index-out-of-bounds in dbAdjTree

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 72244eab0dad Linux 5.15.170
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15037630580000
kernel config: https://syzkaller.appspot.com/x/.config?x=def55f6ee76325cd
dashboard link: https://syzkaller.appspot.com/bug?extid=b15dcf65907dd581fb1c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8aa1e6d5dd83/disk-72244eab.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a87d88d4d204/vmlinux-72244eab.xz
kernel image: https://storage.googleapis.com/syzbot-assets/af75c47a06ad/bzImage-72244eab.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b15dcf...@syzkaller.appspotmail.com

================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2968:18
index -3 is out of range for type 's8[1365]' (aka 'signed char[1365]')
CPU: 1 PID: 4922 Comm: syz.4.154 Not tainted 5.15.170-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_out_of_bounds+0x118/0x140 lib/ubsan.c:282
dbAdjTree+0x377/0x520 fs/jfs/jfs_dmap.c:2968
dbAllocBits+0x4e5/0x9a0 fs/jfs/jfs_dmap.c:2259
dbAllocDmap+0x6d/0x150 fs/jfs/jfs_dmap.c:2100
dbAlloc+0x505/0xc90 fs/jfs/jfs_dmap.c:816
extBalloc fs/jfs/jfs_extent.c:523 [inline]
extAlloc+0x4f4/0x1000 fs/jfs/jfs_extent.c:125
jfs_get_block+0x417/0xe50 fs/jfs/inode.c:258
nobh_write_begin+0x398/0xda0 fs/buffer.c:2650
jfs_write_begin+0x3e/0x80 fs/jfs/inode.c:322
generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
__generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944
__kernel_write+0x5b1/0xa60 fs/read_write.c:539
__dump_emit+0x264/0x3a0 fs/coredump.c:875
dump_user_range+0x91/0x320 fs/coredump.c:949
elf_core_dump+0x3c7d/0x4570 fs/binfmt_elf.c:2285
do_coredump+0x1852/0x31e0 fs/coredump.c:826
get_signal+0xc06/0x14e0 kernel/signal.c:2886
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4846ee6719
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:00007ffff5e3ffc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 00000000000000ca RBX: 00007f484709df88 RCX: 00007f4846ee6719
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f484709df88
RBP: 00007f484709df8c R08: 0000000000000000 R09: 00007ffff5e402bf
R10: 00007f484709df80 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f484709df80 R14: 0000000000000005 R15: 00000000000011e4
</TASK>
================================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 0a51d2d4527b Linux 5.15.173
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15f578f8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=48dad5136d11d5fc

dashboard link: https://syzkaller.appspot.com/bug?extid=b15dcf65907dd581fb1c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12907b30580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16907b30580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/df502ed32946/disk-0a51d2d4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a6f49f24ceaa/vmlinux-0a51d2d4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f45db4b68abf/bzImage-0a51d2d4.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/9ff216e6fd70/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b15dcf...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768

================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2968:18
index -3 is out of range for type 's8[1365]' (aka 'signed char[1365]')

CPU: 0 PID: 4164 Comm: syz-executor243 Not tainted 5.15.173-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_out_of_bounds+0x118/0x140 lib/ubsan.c:282
dbAdjTree+0x377/0x520 fs/jfs/jfs_dmap.c:2968
dbAllocBits+0x4e5/0x9a0 fs/jfs/jfs_dmap.c:2259
dbAllocDmap+0x6d/0x150 fs/jfs/jfs_dmap.c:2100
dbAlloc+0x505/0xc90 fs/jfs/jfs_dmap.c:816
extBalloc fs/jfs/jfs_extent.c:523 [inline]
extAlloc+0x4f4/0x1000 fs/jfs/jfs_extent.c:125
jfs_get_block+0x417/0xe50 fs/jfs/inode.c:258
nobh_write_begin+0x398/0xda0 fs/buffer.c:2650
jfs_write_begin+0x3e/0x80 fs/jfs/inode.c:322
generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
__generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944

call_write_iter include/linux/fs.h:2174 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0xacd/0xe50 fs/read_write.c:594
ksys_write+0x1a2/0x2c0 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f60a1724c99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcb86e3e18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f60a1724c99
RDX: 00000000fffffcf8 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f60a179e5f0 R08: 00000000200205c3 R09: 00005555743604c0
R10: 000000002001a240 R11: 0000000000000246 R12: 00007ffcb86e3e40
R13: 00007ffcb86e4068 R14: 431bde82d7b634db R15: 00007f60a176d03b
</TASK>
================================================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

syzbot suspects this issue was fixed by commit:

commit a3d408870bc19b794646871bc4c3a5daa66f91c5
Author: Nihar Chaithanya <niharch...@gmail.com>
Date: Tue Oct 8 20:21:38 2024 +0000

jfs: add a check to prevent array-index-out-of-bounds in dbAdjTree

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14ea7424580000
start commit: 0a51d2d4527b Linux 5.15.173
git tree: linux-5.15.y

kernel config: https://syzkaller.appspot.com/x/.config?x=48dad5136d11d5fc
dashboard link: https://syzkaller.appspot.com/bug?extid=b15dcf65907dd581fb1c

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12907b30580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16907b30580000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: jfs: add a check to prevent array-index-out-of-bounds in dbAdjTree

For information about bisection process see: https://goo.gl/tpsmEJ#bisection