Linux Kernel up to 6.0.9 s390 current_stack_pointer stack-based overflow

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.0.9. It has been classified as critical. Affected by this vulnerability is the function current_stack_pointer of the component s390. This manipulation causes stack-based overflow. This vulnerability is registered as CVE-2022-49804. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.0.9. Affected by this vulnerability is the function current_stack_pointer of the component s390. The manipulation with an unknown input leads to a stack-based overflow vulnerability. The CWE definition for the vulnerability is CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: s390: avoid using global register for current_stack_pointer Commit 30de14b1884b ("s390: current_stack_pointer shouldn't be a function") made current_stack_pointer a global register variable like on many other architectures. Unfortunately on s390 it uncovers old gcc bug which is fixed only since gcc-9.1 [gcc commit 3ad7fed1cc87 ("S/390: Fix PR89775. Stackpointer save/restore instructions removed")] and backported to gcc-8.4 and later. Due to this bug gcc versions prior to 8.4 generate broken code which leads to stack corruptions. Current minimal gcc version required to build the kernel is declared as 5.1. It is not possible to fix all old gcc versions, so work around this problem by avoiding using global register variable for current_stack_pointer.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2022-49804 since 05/01/2025. The exploitation appears to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/07/2025).

Upgrading to version 6.0.10 eliminates this vulnerability. Applying the patch a478952a8ac44e32316dc046a063a7dc34825aa6/e3c11025bcd2142a61abe5806b2f86a0e78118df 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

• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4
• 6.0.5
• 6.0.6
• 6.0.7
• 6.0.8
• 6.0.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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