Bug 2273715 (CVE-2024-31852)

Summary: CVE-2024-31852 llvm: LR register can be overwritten without data being saved to the stack on ARM
Product: [Other] Security Response Reporter: Robb Gatica <rgatica>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedCC: bodavis, fweimer, ganandan, jistone, mnewsome, sipoyare, tstellar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A miscompile flaw was found in LLVM. In certain conditions, the LR register can be overwritten without data being saved to the stack, which can lead to an exploitable error in the compiled code. This affects the ARM backend and can be demonstrated with Clang.
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Bug Depends On: 2273716, 2273717    
Bug Blocks: 2273709    

Description Robb Gatica 2024-04-05 20:20:40 UTC 
LLVM before 18.1.3 generates code in which the LR register can be overwritten without data being saved to the stack, and thus there can sometimes be an exploitable error in the flow of control. This affects the ARM backend and can be demonstrated with Clang. NOTE: the vendor perspective is "we don't have strong objections for a CVE to be created ... It does seem that the likelihood of this miscompile enabling an exploit remains very low, because the miscompile resulting in this JOP gadget is such that the function is most likely to crash on most valid inputs to the function. So, if this function is covered by any testing, the miscompile is most likely to be discovered before the binary is shipped to production."

https://bugs.chromium.org/p/llvm/issues/detail?id=69
https://github.com/llvm/llvm-project/issues/80287
https://github.com/llvmbot/llvm-project/commit/0e16af8e4cf3a66ad5d078d52744ae2776f9c4b2
https://llvm.org/docs/Security.html
Comment 1 Robb Gatica 2024-04-05 20:24:22 UTC 
Created llvm tracking bugs for this issue:

Affects: fedora-all [bug 2273716]