From: Kim Phillips <kim.phillips@amd.com> stable inclusion from stable-v5.10.105 commit 2fdf67a1d215574c31b1a716f80fa0fdccd401d7 category: bugfix bugzilla: 186453 https://gitee.com/src-openeuler/kernel/issues/I50WBM CVE: CVE-2022-0001 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 244d00b5dd4755f8df892c86cab35fb2cfd4f14b upstream. AMD retpoline may be susceptible to speculation. The speculation execution window for an incorrect indirect branch prediction using LFENCE/JMP sequence may potentially be large enough to allow exploitation using Spectre V2. By default, don't use retpoline,lfence on AMD. Instead, use the generic retpoline. Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com> Reviewed-by: Liao Chang <liaochang1@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- arch/x86/kernel/cpu/bugs.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index e97ab5ca9358..935a4812a442 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -904,15 +904,6 @@ static enum spectre_v2_mitigation __init spectre_v2_select_retpoline(void) return SPECTRE_V2_NONE; } - if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD || - boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) { - if (!boot_cpu_has(X86_FEATURE_LFENCE_RDTSC)) { - pr_err("LFENCE not serializing, switching to generic retpoline\n"); - return SPECTRE_V2_RETPOLINE; - } - return SPECTRE_V2_LFENCE; - } - return SPECTRE_V2_RETPOLINE; } -- 2.20.1