[v6.1] KASAN: null-ptr-deref Write in udf_bread

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 024f76bca9d0 Linux 6.1.49
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=156cfdb7a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=3a51973e83fb3785
dashboard link: https://syzkaller.appspot.com/bug?extid=a38e34ca637c224f4a79
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/c92f407988df/disk-024f76bc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dc4628bc4f9e/vmlinux-024f76bc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f5237e661249/bzImage-024f76bc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a38e34...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: null-ptr-deref in test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:57 [inline]
BUG: KASAN: null-ptr-deref in trylock_buffer include/linux/buffer_head.h:390 [inline]
BUG: KASAN: null-ptr-deref in lock_buffer include/linux/buffer_head.h:396 [inline]
BUG: KASAN: null-ptr-deref in udf_getblk fs/udf/inode.c:474 [inline]
BUG: KASAN: null-ptr-deref in udf_bread+0x29f/0x4b0 fs/udf/inode.c:1192
Write of size 8 at addr 0000000000000000 by task syz-executor.4/2447

CPU: 1 PID: 2447 Comm: syz-executor.4 Not tainted 6.1.49-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106
print_report+0xe6/0x4f0 mm/kasan/report.c:398
kasan_report+0x136/0x160 mm/kasan/report.c:495
kasan_check_range+0x27f/0x290 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:57 [inline]
trylock_buffer include/linux/buffer_head.h:390 [inline]
lock_buffer include/linux/buffer_head.h:396 [inline]
udf_getblk fs/udf/inode.c:474 [inline]
udf_bread+0x29f/0x4b0 fs/udf/inode.c:1192
udf_add_entry+0x1d1e/0x3350 fs/udf/namei.c:495
udf_add_nondir+0x132/0x5d0 fs/udf/namei.c:588
lookup_open fs/namei.c:3413 [inline]
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x12f1/0x2e60 fs/namei.c:3711
do_filp_open+0x230/0x480 fs/namei.c:3741
do_sys_openat2+0x13b/0x500 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fbc2087cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbc216150c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbc2099c050 RCX: 00007fbc2087cae9
RDX: 000000000000275a RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 00007fbc208c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fbc2099c050 R15: 00007ffe614df4d8
</TASK>
==================================================================


---
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#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 082280fe94a0 Linux 6.1.57
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16a36f29680000
kernel config: https://syzkaller.appspot.com/x/.config?x=2fcfda4f62e1716c

dashboard link: https://syzkaller.appspot.com/bug?extid=a38e34ca637c224f4a79
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=12c8a109680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16f15619680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/13811dd7bcb9/disk-082280fe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/78b9e829ec6f/vmlinux-082280fe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2d5fc66b2352/bzImage-082280fe.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/8f041aa6f467/mount_1.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a38e34...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: null-ptr-deref in test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:57 [inline]
BUG: KASAN: null-ptr-deref in trylock_buffer include/linux/buffer_head.h:390 [inline]
BUG: KASAN: null-ptr-deref in lock_buffer include/linux/buffer_head.h:396 [inline]
BUG: KASAN: null-ptr-deref in udf_getblk fs/udf/inode.c:474 [inline]

BUG: KASAN: null-ptr-deref in udf_bread+0x29f/0x4b0 fs/udf/inode.c:1202
Write of size 8 at addr 0000000000000000 by task syz-executor805/3544

CPU: 0 PID: 3544 Comm: syz-executor805 Not tainted 6.1.57-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023

Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
print_report+0xe6/0x4f0 mm/kasan/report.c:398
kasan_report+0x136/0x160 mm/kasan/report.c:495
kasan_check_range+0x27f/0x290 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
test_and_set_bit_lock include/asm-generic/bitops/instrumented-lock.h:57 [inline]
trylock_buffer include/linux/buffer_head.h:390 [inline]
lock_buffer include/linux/buffer_head.h:396 [inline]
udf_getblk fs/udf/inode.c:474 [inline]

udf_bread+0x29f/0x4b0 fs/udf/inode.c:1202

udf_add_entry+0x1d1e/0x3350 fs/udf/namei.c:495
udf_add_nondir+0x132/0x5d0 fs/udf/namei.c:588
lookup_open fs/namei.c:3413 [inline]
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x12f1/0x2e60 fs/namei.c:3711
do_filp_open+0x230/0x480 fs/namei.c:3741
do_sys_openat2+0x13b/0x500 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

RIP: 0033:0x7f5793766ed9
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:00007ffc80866f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffc80866f40 RCX: 00007f5793766ed9
RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 00007f57937db5f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc80866f40
R13: 00007ffc808671a8 R14: 431bde82d7b634db R15: 00007f57937b003b
</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 could be fixed by backporting the following commit:

commit 32f123a3f34283f9c6446de87861696f0502b02e
git tree: upstream
Author: Jan Kara <ja...@suse.cz>
Date: Wed Jan 18 14:33:41 2023 +0000

udf: Fold udf_getblk() into udf_bread()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13acd506e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=2fcfda4f62e1716c
dashboard link: https://syzkaller.appspot.com/bug?extid=a38e34ca637c224f4a79

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c8a109680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16f15619680000

Please keep in mind that other backports might be required as well.

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