[syzbot] [udf?] UBSAN: array-index-out-of-bounds in udf_process_sequence

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0a8db05b571a Merge tag 'platform-drivers-x86-v6.5-3' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=145f2726a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=5d10d93e1ae1f229
dashboard link: https://syzkaller.appspot.com/bug?extid=abb7222a58e4ebc930ad
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/58a518a693f4/disk-0a8db05b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/22cc85e51a4d/vmlinux-0a8db05b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/daeac90304b9/bzImage-0a8db05b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+abb722...@syzkaller.appspotmail.com

================================================================================
UBSAN: array-index-out-of-bounds in fs/udf/super.c:1365:9
index 4 is out of range for type '__le32[4]' (aka 'unsigned int[4]')
CPU: 0 PID: 10089 Comm: syz-executor.0 Not tainted 6.5.0-rc3-syzkaller-00044-g0a8db05b571a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348
udf_load_sparable_map fs/udf/super.c:1365 [inline]
udf_load_logicalvol fs/udf/super.c:1457 [inline]
udf_process_sequence+0x300d/0x4e70 fs/udf/super.c:1773
udf_load_sequence fs/udf/super.c:1820 [inline]
udf_check_anchor_block+0x2a6/0x550 fs/udf/super.c:1855
udf_scan_anchors fs/udf/super.c:1909 [inline]
udf_load_vrs+0xa71/0x1100 fs/udf/super.c:1969
udf_fill_super+0x95d/0x23a0 fs/udf/super.c:2147
mount_bdev+0x276/0x3b0 fs/super.c:1391
legacy_get_tree+0xef/0x190 fs/fs_context.c:611
vfs_get_tree+0x8c/0x270 fs/super.c:1519
do_new_mount+0x28f/0xae0 fs/namespace.c:3335
do_mount fs/namespace.c:3675 [inline]
__do_sys_mount fs/namespace.c:3884 [inline]
__se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f838747e22a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f838819eee8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f838819ef80 RCX: 00007f838747e22a
RDX: 0000000020000100 RSI: 0000000020000200 RDI: 00007f838819ef40
RBP: 0000000020000100 R08: 00007f838819ef80 R09: 0000000000214856
R10: 0000000000214856 R11: 0000000000000202 R12: 0000000020000200
R13: 00007f838819ef40 R14: 0000000000000c1d R15: 0000000020000240
</TASK>
================================================================================


---
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See https://goo.gl/tpsmEJ for more information about syzbot.
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If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to change bug's subsystems, reply with:
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(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, 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: 9e6c269de404 Merge tag 'i2c-for-6.5-rc7' of git://git.kern..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=139aa5efa80000
kernel config: https://syzkaller.appspot.com/x/.config?x=9c37cc0e4fcc5f8d

dashboard link: https://syzkaller.appspot.com/bug?extid=abb7222a58e4ebc930ad
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=175ed6bba80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=146c8923a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1d01305b8482/disk-9e6c269d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d7317878934a/vmlinux-9e6c269d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a7333ff86494/bzImage-9e6c269d.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/2ad8331a86f3/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/049e481cc897/mount_8.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+abb722...@syzkaller.appspotmail.com

UBSAN: array-index-out-of-bounds in fs/udf/super.c:1365:9
index 4 is out of range for type '__le32[4]' (aka 'unsigned int[4]')

CPU: 0 PID: 6060 Comm: syz-executor319 Not tainted 6.5.0-rc6-syzkaller-00253-g9e6c269de404 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023

Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348
udf_load_sparable_map fs/udf/super.c:1365 [inline]
udf_load_logicalvol fs/udf/super.c:1457 [inline]
udf_process_sequence+0x300d/0x4e70 fs/udf/super.c:1773
udf_load_sequence fs/udf/super.c:1820 [inline]
udf_check_anchor_block+0x2a6/0x550 fs/udf/super.c:1855

udf_scan_anchors fs/udf/super.c:1888 [inline]
udf_load_vrs+0x5ca/0x1100 fs/udf/super.c:1969

udf_fill_super+0x95d/0x23a0 fs/udf/super.c:2147
mount_bdev+0x276/0x3b0 fs/super.c:1391
legacy_get_tree+0xef/0x190 fs/fs_context.c:611
vfs_get_tree+0x8c/0x270 fs/super.c:1519
do_new_mount+0x28f/0xae0 fs/namespace.c:3335
do_mount fs/namespace.c:3675 [inline]
__do_sys_mount fs/namespace.c:3884 [inline]
__se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

RIP: 0033:0x7f363cae1c8a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 3e 07 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffe6eac67a8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f363cae1c8a
RDX: 0000000020000100 RSI: 0000000020000340 RDI: 00007ffe6eac6800
RBP: 00007ffe6eac6840 R08: 00007ffe6eac6840 R09: 0000000000000c35
R10: 0000000000000000 R11: 0000000000000282 R12: 0000000020000340
R13: 0000000020000100 R14: 0000000000000c3b R15: 0000000020020500
</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.

[Jan Kara]

On Sun 20-08-23 07:25:47, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 9e6c269de404 Merge tag 'i2c-for-6.5-rc7' of git://git.kern..
> git tree: upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=139aa5efa80000
> kernel config: https://syzkaller.appspot.com/x/.config?x=9c37cc0e4fcc5f8d
> dashboard link: https://syzkaller.appspot.com/bug?extid=abb7222a58e4ebc930ad
> 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=175ed6bba80000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=146c8923a80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/1d01305b8482/disk-9e6c269d.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/d7317878934a/vmlinux-9e6c269d.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/a7333ff86494/bzImage-9e6c269d.xz
> mounted in repro #1: https://storage.googleapis.com/syzbot-assets/2ad8331a86f3/mount_0.gz
> mounted in repro #2: https://storage.googleapis.com/syzbot-assets/049e481cc897/mount_8.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+abb722...@syzkaller.appspotmail.com
>
> UBSAN: array-index-out-of-bounds in fs/udf/super.c:1365:9
> index 4 is out of range for type '__le32[4]' (aka 'unsigned int[4]')

Frankly, the report doesn't make sense to me. The code looks like:

if (spm->numSparingTables > 4) {
bail out
}

for (i = 0; i < spm->numSparingTables; i++) {
loc = le32_to_cpu(spm->locSparingTable[i]);
...
}

and UBSAN complains when i == 4 which should not be possible. The only way
how I see this could be possible is when syzbot somehow manages to corrupt
the buffer 'spm' is stored in after we check it but so far I don't
see that in the reproducer and if that would really happen this would not
be anything to fix in UDF...

Honza

--
Jan Kara <ja...@suse.com>
SUSE Labs, CR

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 6f861765464f43a71462d52026fbddfc858239a5
Author: Jan Kara <ja...@suse.cz>
Date: Wed Nov 1 17:43:10 2023 +0000

fs: Block writes to mounted block devices

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17ef13dc180000
start commit: 9e6c269de404 Merge tag 'i2c-for-6.5-rc7' of git://git.kern..
git tree: upstream

kernel config: https://syzkaller.appspot.com/x/.config?x=9c37cc0e4fcc5f8d
dashboard link: https://syzkaller.appspot.com/bug?extid=abb7222a58e4ebc930ad

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175ed6bba80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=146c8923a80000

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

#syz fix: fs: Block writes to mounted block devices

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

[Jan Kara]

On Thu 15-02-24 09:30:02, syzbot wrote:
> syzbot suspects this issue was fixed by commit:
>
> commit 6f861765464f43a71462d52026fbddfc858239a5
> Author: Jan Kara <ja...@suse.cz>
> Date: Wed Nov 1 17:43:10 2023 +0000
>
> fs: Block writes to mounted block devices
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17ef13dc180000
> start commit: 9e6c269de404 Merge tag 'i2c-for-6.5-rc7' of git://git.kern..
> git tree: upstream
> kernel config: https://syzkaller.appspot.com/x/.config?x=9c37cc0e4fcc5f8d
> dashboard link: https://syzkaller.appspot.com/bug?extid=abb7222a58e4ebc930ad
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175ed6bba80000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=146c8923a80000
>
> If the result looks correct, please mark the issue as fixed by replying with:

Makes sense.

#syz fix: fs: Block writes to mounted block devices

Honza