Message-ID: <2025050142-CVE-2022-49846-728c@gregkh>
Date: Thu,  1 May 2025 16:10:36 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2022-49846: udf: Fix a slab-out-of-bounds write bug in udf_find_entry()

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

udf: Fix a slab-out-of-bounds write bug in udf_find_entry()

Syzbot reported a slab-out-of-bounds Write bug:

loop0: detected capacity change from 0 to 2048
==================================================================
BUG: KASAN: slab-out-of-bounds in udf_find_entry+0x8a5/0x14f0
fs/udf/namei.c:253
Write of size 105 at addr ffff8880123ff896 by task syz-executor323/3610

CPU: 0 PID: 3610 Comm: syz-executor323 Not tainted
6.1.0-rc2-syzkaller-00105-gb229b6ca5abb #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS
Google 10/11/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 print_address_description+0x74/0x340 mm/kasan/report.c:284
 print_report+0x107/0x1f0 mm/kasan/report.c:395
 kasan_report+0xcd/0x100 mm/kasan/report.c:495
 kasan_check_range+0x2a7/0x2e0 mm/kasan/generic.c:189
 memcpy+0x3c/0x60 mm/kasan/shadow.c:66
 udf_find_entry+0x8a5/0x14f0 fs/udf/namei.c:253
 udf_lookup+0xef/0x340 fs/udf/namei.c:309
 lookup_open fs/namei.c:3391 [inline]
 open_last_lookups fs/namei.c:3481 [inline]
 path_openat+0x10e6/0x2df0 fs/namei.c:3710
 do_filp_open+0x264/0x4f0 fs/namei.c:3740
 do_sys_openat2+0x124/0x4e0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_creat fs/open.c:1402 [inline]
 __se_sys_creat fs/open.c:1396 [inline]
 __x64_sys_creat+0x11f/0x160 fs/open.c:1396
 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: 0033:0x7ffab0d164d9
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:00007ffe1a7e6bb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffab0d164d9
RDX: 00007ffab0d164d9 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 00007ffab0cd5a10 R08: 0000000000000000 R09: 0000000000000000
R10: 00005555573552c0 R11: 0000000000000246 R12: 00007ffab0cd5aa0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 3610:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x3d/0x60 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:371 [inline]
 __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:380
 kmalloc include/linux/slab.h:576 [inline]
 udf_find_entry+0x7b6/0x14f0 fs/udf/namei.c:243
 udf_lookup+0xef/0x340 fs/udf/namei.c:309
 lookup_open fs/namei.c:3391 [inline]
 open_last_lookups fs/namei.c:3481 [inline]
 path_openat+0x10e6/0x2df0 fs/namei.c:3710
 do_filp_open+0x264/0x4f0 fs/namei.c:3740
 do_sys_openat2+0x124/0x4e0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_creat fs/open.c:1402 [inline]
 __se_sys_creat fs/open.c:1396 [inline]
 __x64_sys_creat+0x11f/0x160 fs/open.c:1396
 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

The buggy address belongs to the object at ffff8880123ff800
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 150 bytes inside of
 256-byte region [ffff8880123ff800, ffff8880123ff900)

The buggy address belongs to the physical page:
page:ffffea000048ff80 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x123fe
head:ffffea000048ff80 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea00004b8500 dead000000000003 ffff888012041b40
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x0(),
pid 1, tgid 1 (swapper/0), ts 1841222404, free_ts 0
 create_dummy_stack mm/page_owner.c:67 [inline]
 register_early_stack+0x77/0xd0 mm/page_owner.c:83
 init_page_owner+0x3a/0x731 mm/page_owner.c:93
 kernel_init_freeable+0x41c/0x5d5 init/main.c:1629
 kernel_init+0x19/0x2b0 init/main.c:1519
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880123ff780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880123ff800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880123ff880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06
                                                                ^
 ffff8880123ff900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880123ff980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Fix this by changing the memory size allocated for copy_name from
UDF_NAME_LEN(254) to UDF_NAME_LEN_CS0(255), because the total length
(lfi) of subsequent memcpy can be up to 255.

The Linux kernel CVE team has assigned CVE-2022-49846 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 4.9.334 with commit 583fdd98d94acba1e7225e5cc29063aef0741030
	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 4.14.300 with commit f1517721c408631f09d54c743aa70cb07fd3eebd
	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 4.19.267 with commit 7a6051d734f1ed0031e2216f9a538621235c11a4
	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 5.4.225 with commit d8971f410739a864c537e0ac29344a7b6c450232
	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 5.10.155 with commit 03f9582a6a2ebd25a440896475c968428c4b63e7
	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 5.15.79 with commit c736ed8541605e3a25075bb1cbf8f38cb3083238
	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 6.0.9 with commit ac79001b8e603226fab17240a79cb9ef679d3cd9
	Issue introduced in 4.6 with commit 066b9cded00b8e3212df74a417bb074f3f3a1fe0 and fixed in 6.1 with commit c8af247de385ce49afabc3bf1cf4fd455c94bfe8

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-49846
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	fs/udf/namei.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/583fdd98d94acba1e7225e5cc29063aef0741030
	https://git.kernel.org/stable/c/f1517721c408631f09d54c743aa70cb07fd3eebd
	https://git.kernel.org/stable/c/7a6051d734f1ed0031e2216f9a538621235c11a4
	https://git.kernel.org/stable/c/d8971f410739a864c537e0ac29344a7b6c450232
	https://git.kernel.org/stable/c/03f9582a6a2ebd25a440896475c968428c4b63e7
	https://git.kernel.org/stable/c/c736ed8541605e3a25075bb1cbf8f38cb3083238
	https://git.kernel.org/stable/c/ac79001b8e603226fab17240a79cb9ef679d3cd9
	https://git.kernel.org/stable/c/c8af247de385ce49afabc3bf1cf4fd455c94bfe8

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