CVE-2024-40974

high

Published 2024-08-08 · Modified 2024-08-08

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

8.0

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc/pseries: Enforce hcall result buffer validity and size plpar_hcall(), plpar_hcall9(), and related functions expect callers to provide valid result buffers of certain minimum size. Currently this is communicated only through comments in the code and the compiler has no idea. For example, if I write a bug like this: long retbuf[PLPAR_HCALL_BUFSIZE]; // should be PLPAR_HCALL9_BUFSIZE plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, ...); This compiles with no diagnostics emitted, but likely results in stack corruption at runtime when plpar_hcall9() stores results past the end of the array. (To be clear this is a contrived example and I have not found a real instance yet.) To make this class of error less likely, we can use explicitly-sized array parameters instead of pointers in the declarations for the hcall APIs. When compiled with -Warray-bounds[1], the code above now provokes a diagnostic like this: error: array argument is too small; is of size 32, callee requires at least 72 [-Werror,-Warray-bounds] 60 | plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, | ^ ~~~~~~ [1] Enabled for LLVM builds but not GCC for now. See commit 0da6e5fd6c37 ("gcc: disable '-Warray-bounds' for gcc-13 too") and related changes.

Predictions

Exploit likelihood

20%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

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OS impact

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

AlmaLinux Fixed 1 release

Version	Status	Fixed in
8	Fixed	`kernel-doc-4.18.0-553.16.1.el8_10.noarch.rpm`

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`6.9.7-1`
sid	Fixed	`6.9.7-1`
forky	Fixed	`6.9.7-1`
bullseye	Fixed	`5.10.221-1`
bookworm	Fixed	`6.1.99-1`

Red Hat Fixed 1 release

Version	Status	Fixed in
8	Fixed	—

Rocky Linux Fixed 1 release

Version	Status	Fixed in
8	Fixed	—

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.