KASAN: slab-out-of-bounds Write in udf_write_aext

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14cbd66ab00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=3b27c24cd871399e250f
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=177f0b22b00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3b27c2...@syzkaller.appspotmail.com

wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2020/09/19 18:44 (1000)
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2020/09/19 18:44 (1000)
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
==================================================================
BUG: KASAN: slab-out-of-bounds in udf_write_aext+0x780/0x860 fs/udf/inode.c:2065
Write of size 4 at addr ffff88809b764a30 by task syz-executor.0/9666

CPU: 0 PID: 9666 Comm: syz-executor.0 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_store_n_noabort+0x8b/0xa0 mm/kasan/report.c:449
udf_write_aext+0x780/0x860 fs/udf/inode.c:2065
udf_add_entry+0xdab/0x2a20 fs/udf/namei.c:496
udf_mkdir+0x145/0x650 fs/udf/namei.c:693
vfs_mkdir+0x508/0x7a0 fs/namei.c:3819
do_mkdirat+0x262/0x2d0 fs/namei.c:3842
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff7b742dae9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff7b6b61188 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff7b75410e0 RCX: 00007ff7b742dae9
RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000005
RBP: 00007ff7b7487f25 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc1f84a5df R14: 00007ff7b6b61300 R15: 0000000000022000

Allocated by task 0:
(stack is not available)

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88809b7647c0
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 112 bytes to the right of
512-byte region [ffff88809b7647c0, ffff88809b7649c0)
The buggy address belongs to the page:
page:ffffea00026dd900 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea00027b1a88 ffffea00026aa488 ffff88813bff0940
raw: 0000000000000000 ffff88809b764040 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88809b764900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88809b764980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88809b764a00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
^
ffff88809b764a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88809b764b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y

console output: https://syzkaller.appspot.com/x/log.txt?x=15481904880000

kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=3b27c24cd871399e250f
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16f2dc48880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17984068880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/98c0bdb4abb3/disk-3f8a27f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ea228ff02669/vmlinux-3f8a27f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3b27c2...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in udf_write_aext+0x847/0x860 fs/udf/inode.c:2059
Write of size 4 at addr ffff8880954080b8 by task syz-executor381/8104

CPU: 1 PID: 8104 Comm: syz-executor381 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022

Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_store_n_noabort+0x8b/0xa0 mm/kasan/report.c:449

udf_write_aext+0x847/0x860 fs/udf/inode.c:2059

udf_add_entry+0xdab/0x2a20 fs/udf/namei.c:496
udf_mkdir+0x145/0x650 fs/udf/namei.c:693
vfs_mkdir+0x508/0x7a0 fs/namei.c:3819
do_mkdirat+0x262/0x2d0 fs/namei.c:3842
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

RIP: 0033:0x7fc656f3f519
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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc6151b488 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc656f3f519
RDX: 00000000000001ff RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 00007fc656efeaf0 R08: 00007ffc6151b360 R09: 0000000000000000
R10: 00007ffc6151b350 R11: 0000000000000246 R12: 00007fc656efeb80
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 8104:
__do_kmalloc mm/slab.c:3727 [inline]
__kmalloc+0x15a/0x3c0 mm/slab.c:3736
kmalloc include/linux/slab.h:520 [inline]
kzalloc include/linux/slab.h:709 [inline]
udf_new_inode+0x220/0xf30 fs/udf/ialloc.c:75
udf_mkdir+0xa8/0x650 fs/udf/namei.c:686

vfs_mkdir+0x508/0x7a0 fs/namei.c:3819
do_mkdirat+0x262/0x2d0 fs/namei.c:3842
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6267:
__cache_free mm/slab.c:3503 [inline]
kfree+0xcc/0x210 mm/slab.c:3822
kernfs_fop_release+0x120/0x190 fs/kernfs/file.c:783
__fput+0x2ce/0x890 fs/file_table.c:278
task_work_run+0x148/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:193 [inline]
exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880954080c0

which belongs to the cache kmalloc-512 of size 512

The buggy address is located 8 bytes to the left of
512-byte region [ffff8880954080c0, ffff8880954082c0)

The buggy address belongs to the page:

page:ffffea0002550200 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea000277b688 ffffea0002ca7988 ffff88813bff0940
raw: 0000000000000000 ffff8880954080c0 0000000100000006 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff888095407f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888095408000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888095408080: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
^
ffff888095408100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888095408180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================