https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Sun, 04 Oct 2026 05:46:48 +0000 https://vulnerability.circl.lu/vuln/cve-2023-52504 <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>x86/alternatives: Disable KASAN in apply_alternatives()</p> <p>Fei has reported that KASAN triggers during apply_alternatives() on a 5-level paging machine:</p> <p>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() ...</p> <p>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().</p> <p>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.</p> <p>Fix it for real by disabling KASAN while the kernel is patching alternatives.</p> <p>[ mingo: updated the changelog ]</p> <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>x86/alternatives: Disable KASAN in apply_alternatives()</p> <p>Fei has reported that KASAN triggers during apply_alternatives() on a 5-level paging machine:</p> <p>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() ...</p> <p>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().</p> <p>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.</p> <p>Fix it for real by disabling KASAN while the kernel is patching alternatives.</p> <p>[ mingo: updated the changelog ]</p> https://vulnerability.circl.lu/vuln/cve-2023-52504