Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.6.14/6.7.2. This affects the function page_mapping of the component mm. Executing a manipulation can lead to null pointer dereference. The identification of this vulnerability is CVE-2023-52490. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.14/6.7.2 (Operating System). It has been declared as critical. This vulnerability affects the function page_mapping of the component mm. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mm: migrate: fix getting incorrect page mapping during page migration When running stress-ng testing, we found below kernel crash after a few hours: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 pc : dentry_name+0xd8/0x224 lr : pointer+0x22c/0x370 sp : ffff800025f134c0 ...... Call trace: dentry_name+0xd8/0x224 pointer+0x22c/0x370 vsnprintf+0x1ec/0x730 vscnprintf+0x2c/0x60 vprintk_store+0x70/0x234 vprintk_emit+0xe0/0x24c vprintk_default+0x3c/0x44 vprintk_func+0x84/0x2d0 printk+0x64/0x88 __dump_page+0x52c/0x530 dump_page+0x14/0x20 set_migratetype_isolate+0x110/0x224 start_isolate_page_range+0xc4/0x20c offline_pages+0x124/0x474 memory_block_offline+0x44/0xf4 memory_subsys_offline+0x3c/0x70 device_offline+0xf0/0x120 ...... After analyzing the vmcore, I found this issue is caused by page migration. The scenario is that, one thread is doing page migration, and we will use the target page's ->mapping field to save 'anon_vma' pointer between page unmap and page move, and now the target page is locked and refcount is 1. Currently, there is another stress-ng thread performing memory hotplug, attempting to offline the target page that is being migrated. It discovers that the refcount of this target page is 1, preventing the offline operation, thus proceeding to dump the page. However, page_mapping() of the target page may return an incorrect file mapping to crash the system in dump_mapping(), since the target page->mapping only saves 'anon_vma' pointer without setting PAGE_MAPPING_ANON flag. There are seveval ways to fix this issue: (1) Setting the PAGE_MAPPING_ANON flag for target page's ->mapping when saving 'anon_vma', but this can confuse PageAnon() for PFN walkers, since the target page has not built mappings yet. (2) Getting the page lock to call page_mapping() in __dump_page() to avoid crashing the system, however, there are still some PFN walkers that call page_mapping() without holding the page lock, such as compaction. (3) Using target page->private field to save the 'anon_vma' pointer and 2 bits page state, just as page->mapping records an anonymous page, which can remove the page_mapping() impact for PFN walkers and also seems a simple way. So I choose option 3 to fix this issue, and this can also fix other potential issues for PFN walkers, such as compaction.

The weakness was shared 02/29/2024. The advisory is available at git.kernel.org. This vulnerability was named CVE-2023-52490 since 02/20/2024. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 210815 (RHEL 9 : kernel (RHSA-2024:9315)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.15, 6.7.3 or 6.8-rc1 eliminates this vulnerability. Applying the patch 9128bfbc5c80/3889a418b6eb/d1adb25df711 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 databases at Tenable (210815) and CERT Bund (WID-SEC-2025-1293). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Ubuntu Linux
• IBM DataPower Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.7.0
• 6.7.1
• 6.7.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

Threat Intelligenceinfo

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Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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