Bug 2334438 (CVE-2024-56550)

Summary: CVE-2024-56550 kernel: s390/stacktrace: Use break instead of return statement
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A vulnerability was found in the arch_stack_walk_user_common() function in the Linux kernel's S390 stack trace component, where a logic error can cause a missing pagefault_enable() call. This occurs due to a return statement being used instead of a break, leading to unresolved page faults that can terminate the affected process.
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Description OSIDB Bzimport 2024-12-27 15:02:03 UTC 
In the Linux kernel, the following vulnerability has been resolved:

s390/stacktrace: Use break instead of return statement

arch_stack_walk_user_common() contains a return statement instead of a
break statement in case store_ip() fails while trying to store a callchain
entry of a user space process.
This may lead to a missing pagefault_enable() call.

If this happens any subsequent page fault of the process won't be resolved
by the page fault handler and this in turn will lead to the process being
killed.

Use a break instead of a return statement to fix this.
Comment 1 Avinash Hanwate 2024-12-28 08:51:01 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024122701-CVE-2024-56550-68f3@gregkh/T