Submit #844457: LLVM LLVM Project commit 3b3a3c2 Stack-based Buffer Overflowinfo

TitleLLVM LLVM Project commit 3b3a3c2 Stack-based Buffer Overflow
DescriptionA stack buffer overflow vulnerability exists in LLVM’s ValueSymbolTable module when parsing malformed bitcode files. The actual bug resides in the optimized inline logic of llvm::StringMap::insert(). When processing maliciously crafted bitcode via the llvm-opt-fuzzer (x86_64-gvn pass), incorrect stack offset calculation for temporary stack values during symbol table insertion triggers an out-of-bounds stack write. The faulty assembly instruction mov qword ptr [rbx + 0x48], r12 causes stack corruption and program crash, even when core runtime objects are valid. The vulnerability can be triggered by a custom malicious bitcode PoC. Local attackers can exploit this flaw to crash the affected process, with potential memory corruption and arbitrary code execution risks under specific memory layouts.
Source⚠️ https://github.com/llvm/llvm-project/issues/199187
User
 TYGLS (UID 94774)
Submission06/01/2026 04:50 (28 days ago)
Moderation06/28/2026 20:47 (28 days later)
StatusAccepted
VulDB entry374581 [llvm llvm-project up to 22.1.6 ValueSymbolTable ValueSymbolTable.cpp llvm::StringMap::insert stack-based overflow]
Points20

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