Linux Kernel up to 5.17.3 cachefiles_set_volume_xattr slab-out-of-bounds

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 5.17.3. This affects the function slab-out-of-bounds of the component cachefiles_set_volume_xattr. This manipulation causes out-of-bounds. This vulnerability is registered as CVE-2022-49062. It is feasible to perform the attack on the physical device. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.17.3. Affected by this vulnerability is the function slab-out-of-bounds of the component cachefiles_set_volume_xattr. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix KASAN slab-out-of-bounds in cachefiles_set_volume_xattr Use the actual length of volume coherency data when setting the xattr to avoid the following KASAN report. BUG: KASAN: slab-out-of-bounds in cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] Write of size 4 at addr ffff888101e02af4 by task kworker/6:0/1347 CPU: 6 PID: 1347 Comm: kworker/6:0 Kdump: loaded Not tainted 5.18.0-rc1-nfs-fscache-netfs+ #13 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-4.fc34 04/01/2014 Workqueue: events fscache_create_volume_work [fscache] Call Trace: dump_stack_lvl+0x45/0x5a print_report.cold+0x5e/0x5db ? __lock_text_start+0x8/0x8 ? cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] kasan_report+0xab/0x120 ? cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] kasan_check_range+0xf5/0x1d0 memcpy+0x39/0x60 cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] cachefiles_acquire_volume+0x2be/0x500 [cachefiles] ? __cachefiles_free_volume+0x90/0x90 [cachefiles] fscache_create_volume_work+0x68/0x160 [fscache] process_one_work+0x3b7/0x6a0 worker_thread+0x2c4/0x650 ? process_one_work+0x6a0/0x6a0 kthread+0x16c/0x1a0 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 Allocated by task 1347: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 cachefiles_set_volume_xattr+0x76/0x350 [cachefiles] cachefiles_acquire_volume+0x2be/0x500 [cachefiles] fscache_create_volume_work+0x68/0x160 [fscache] process_one_work+0x3b7/0x6a0 worker_thread+0x2c4/0x650 kthread+0x16c/0x1a0 ret_from_fork+0x22/0x30 The buggy address belongs to the object at ffff888101e02af0 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 4 bytes inside of 8-byte region [ffff888101e02af0, ffff888101e02af8) The buggy address belongs to the physical page: page:00000000a2292d70 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101e02 flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) raw: 0017ffffc0000200 0000000000000000 dead000000000001 ffff888100042280 raw: 0000000000000000 0000000080660066 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888101e02980: fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc ffff888101e02a00: 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc 00 >ffff888101e02a80: fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc 04 fc ^ ffff888101e02b00: fc fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc ffff888101e02b80: fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc ==================================================================

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2022-49062 since 02/26/2025. The exploitation appears to be difficult. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 5.17.4 eliminates this vulnerability. Applying the patch 09a5df1b88c8f126c8ff9938edf160edd4e92f42/7b2f6c306601240635c72caa61f682e74d4591b2 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.17.0
• 5.17.1
• 5.17.2
• 5.17.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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