CVE-2023-52504
In the Linux kernel, the following vulnerability has been resolved: x86/alternatives: Disable KASAN in apply_alternatives() Fei has reported that KASAN triggers during apply_alternatives() on a 5-level paging machine: BUG: KASAN: out-of-bounds in…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: x86/alternatives: Disable KASAN in apply_alternatives() Fei has reported that KASAN triggers during apply_alternatives() on a 5-level paging machine: BUG: KASAN: out-of-bounds in rcu_is_watching() Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0 ... __asan_load4() rcu_is_watching() trace_hardirqs_on() text_poke_early() apply_alternatives() ... On machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57) gets patched. It includes KASAN code, where KASAN_SHADOW_START depends on __VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled(). KASAN gets confused when apply_alternatives() patches the KASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START static, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue. Fix it for real by disabling KASAN while the kernel is patching alternatives. [ mingo: updated the changelog ]
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 0.28% probability · 20th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/3719d3c36aa853d5a2401af9f8d6b116c91ad5aePatch
- https://git.kernel.org/stable/c/3770c38cd6a60494da29ac2da73ff8156440a2d1Patch
- https://git.kernel.org/stable/c/5b784489c8158518bf7a466bb3cc045b0fb66b4bPatch
- https://git.kernel.org/stable/c/6788b10620ca6e98575d1e06e72a8974aad7657ePatch
- https://git.kernel.org/stable/c/cd287cc208dfe6bd6da98e7f88e723209242c9b4Patch
- https://git.kernel.org/stable/c/d35652a5fc9944784f6f50a5c979518ff8dacf61Patch
- https://git.kernel.org/stable/c/ecba5afe86f30605eb9dfb7f265a8de0218d4cfcPatch
- https://git.kernel.org/stable/c/3719d3c36aa853d5a2401af9f8d6b116c91ad5aePatch
- https://git.kernel.org/stable/c/3770c38cd6a60494da29ac2da73ff8156440a2d1Patch
- https://git.kernel.org/stable/c/5b784489c8158518bf7a466bb3cc045b0fb66b4bPatch
- https://git.kernel.org/stable/c/6788b10620ca6e98575d1e06e72a8974aad7657ePatch
- https://git.kernel.org/stable/c/cd287cc208dfe6bd6da98e7f88e723209242c9b4Patch
- https://git.kernel.org/stable/c/d35652a5fc9944784f6f50a5c979518ff8dacf61Patch
- https://git.kernel.org/stable/c/ecba5afe86f30605eb9dfb7f265a8de0218d4cfcPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.