Bug 2513480 (CVE-2026-68151)

Summary: CVE-2026-68151 kernel: binfmt_elf_fdpic: only honour the first PT_INTERP
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `binfmt_elf_fdpic` component. This component, which handles FDPIC ELF binaries, does not correctly process multiple `PT_INTERP` program headers. An unprivileged local attacker can exploit this by crafting a malicious binary with more than one `PT_INTERP` header. Successful exploitation leads to a resource leak where a file remains unwritable indefinitely, causing a denial of service.
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Description OSIDB Bzimport 2026-08-10 12:39:43 UTC
In the Linux kernel, the following vulnerability has been resolved:

binfmt_elf_fdpic: only honour the first PT_INTERP

The program header scan handles PT_INTERP from a switch nested in the
scan loop, so its break leaves the switch and not the loop. A binary
carrying more than one PT_INTERP runs the case again and overwrites both
interpreter_name and interpreter. The previous name allocation leaks and
so does the previous interpreter reference, along with the write denial
open_exec() took on it. The denial is never released, so the file stays
unwritable for as long as the system runs.

An unprivileged caller reaches this with a crafted binary and repeats it
at will. binfmt_elf stops at the first PT_INTERP. Do the same here.

The flaw dates back to the driver's introduction in the pre-git history
tree introduced in v2.6.11 by 91808d6ebe39 ("[PATCH] FRV: Add FDPIC ELF
binary format driver").

Comment 1 Mauro Matteo Cascella 2026-08-11 07:53:05 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081002-CVE-2026-68151-36d7@gregkh/T