Linux Kernel up to 5.17.1 lib/xarray.c xas_create_range null pointer dereference

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.4.188/5.10.109/5.15.32/5.16.18/5.17.1 and classified as critical. This vulnerability affects the function xas_create_range in the library lib/xarray.c. Such manipulation leads to null pointer dereference. This vulnerability is documented as CVE-2022-49152. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.4.188/5.10.109/5.15.32/5.16.18/5.17.1. It has been rated as critical. Affected by this issue is the function xas_create_range in the library lib/xarray.c. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: XArray: Fix xas_create_range() when multi-order entry present If there is already an entry present that is of order >= XA_CHUNK_SHIFT when we call xas_create_range(), xas_create_range() will misinterpret that entry as a node and dereference xa_node->parent, generally leading to a crash that looks something like this: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 32 Comm: khugepaged Not tainted 5.17.0-rc8-syzkaller-00003-g56e337f2cf13 #0 RIP: 0010:xa_parent_locked include/linux/xarray.h:1207 [inline] RIP: 0010:xas_create_range+0x2d9/0x6e0 lib/xarray.c:725 It's deterministically reproducable once you know what the problem is, but producing it in a live kernel requires khugepaged to hit a race. While the problem has been present since xas_create_range() was introduced, I'm not aware of a way to hit it before the page cache was converted to use multi-index entries.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2022-49152 since 02/26/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

Upgrading to version 5.4.189, 5.10.110, 5.15.33, 5.16.19 or 5.17.2 eliminates this vulnerability. Applying the patch 3e2852eda19ee1a400cd809d7a9322680f34a262/1ac49c8fd49fdf53d3cd8b77eb8ffda08d7fbe22/7521a97b1929042604bef6859f62fa8b4bbc077b/29968329b926d238e3107ec071a250397555d264/18f13edf3424b3b61814b69d5269b2e14584800c/3e3c658055c002900982513e289398a1aad4a488 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.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2022-55073). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.188
• 5.10.109
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.16.0
• 5.16.1
• 5.16.2
• 5.16.3
• 5.16.4
• 5.16.5
• 5.16.6
• 5.16.7
• 5.16.8
• 5.16.9
• 5.16.10
• 5.16.11
• 5.16.12
• 5.16.13
• 5.16.14
• 5.16.15
• 5.16.16
• 5.16.17
• 5.16.18
• 5.17.0
• 5.17.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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