CVE-2024-26710: powerpc/kasan: Limit KASAN thread size increase to 32KB
Description
In the Linux kernel, the following vulnerability has been resolved:
powerpc/kasan: Limit KASAN thread size increase to 32KB
KASAN is seen to increase stack usage, to the point that it was reported
to lead to stack overflow on some 32-bit machines (see link).
To avoid overflows the stack size was doubled for KASAN builds in
commit 3e8635fb2e07 ("powerpc/kasan: Force thread size increase with
KASAN").
However with a 32KB stack size to begin with, the doubling leads to a
64KB stack, which causes build errors:
arch/powerpc/kernel/switch.S:249: Error: operand out of range (0x000000000000fe50 is not between 0xffffffffffff8000 and 0x0000000000007fff)
Although the asm could be reworked, in practice a 32KB stack seems
sufficient even for KASAN builds - the additional usage seems to be in
the 2-3KB range for a 64-bit KASAN build.
So only increase the stack for KASAN if the stack size is < 32KB.
Classification
CVE ID: CVE-2024-26710
Affected Products
Vendor: Linux
Product: Linux
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.05% (probability of being exploited)
EPSS Percentile: 17.97% (scored less or equal to compared to others)
EPSS Date: 2025-02-21 (when was this score calculated)
References
https://git.kernel.org/stable/c/4297217bcf1f0948a19c2bacc6b68d92e7778ad9https://git.kernel.org/stable/c/4cc31fa07445879a13750cb061bb8c2654975fcb
https://git.kernel.org/stable/c/b29b16bd836a838b7690f80e37f8376414c74cbe
https://git.kernel.org/stable/c/f1acb109505d983779bbb7e20a1ee6244d2b5736