漏洞信息
# ARM64:SME中使用STR P清除FFR上下文字段漏洞
N/A
提示
尽管我们采用了先进的大模型技术,但其输出仍可能包含不准确或过时的信息。
神龙会尽力确保数据准确,但也请结合实际情况进行甄别与判断。
神龙祝您一切顺利!
漏洞标题
arm64: sme: Use STR P to clear FFR context field in streaming SVE mode
漏洞描述信息
In the Linux kernel, the following vulnerability has been resolved:
arm64: sme: Use STR P to clear FFR context field in streaming SVE mode
The FFR is a predicate register which can vary between 16 and 256 bits
in size depending upon the configured vector length. When saving the
SVE state in streaming SVE mode, the FFR register is inaccessible and
so commit 9f5848665788 ("arm64/sve: Make access to FFR optional") simply
clears the FFR field of the in-memory context structure. Unfortunately,
it achieves this using an unconditional 8-byte store and so if the SME
vector length is anything other than 64 bytes in size we will either
fail to clear the entire field or, worse, we will corrupt memory
immediately following the structure. This has led to intermittent kfence
splats in CI [1] and can trigger kmalloc Redzone corruption messages
when running the 'fp-stress' kselftest:
| =============================================================================
| BUG kmalloc-1k (Not tainted): kmalloc Redzone overwritten
| -----------------------------------------------------------------------------
|
| 0xffff000809bf1e22-0xffff000809bf1e27 @offset=7714. First byte 0x0 instead of 0xcc
| Allocated in do_sme_acc+0x9c/0x220 age=2613 cpu=1 pid=531
| __kmalloc+0x8c/0xcc
| do_sme_acc+0x9c/0x220
| ...
Replace the 8-byte store with a store of a predicate register which has
been zero-initialised with PFALSE, ensuring that the entire field is
cleared in memory.
[1] https://lore.kernel.org/r/CA+G9fYtU7HsV0R0dp4XEH5xXHSJFw8KyDf5VQrLLfMxWfxQkag@mail.gmail.com
CVSS信息
N/A
漏洞类别
N/A
漏洞标题
Linux kernel 安全漏洞
漏洞描述信息
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞,该漏洞源于在流式SVE模式下使用不当存储指令清除FFR上下文字段,可能导致内存损坏。
CVSS信息
N/A
漏洞类别
其他