diff options
Diffstat (limited to 'debian/patches/bugfix/x86/retbleed/0026-x86-bugs-Report-Intel-retbleed-vulnerability.patch')
| -rw-r--r-- | debian/patches/bugfix/x86/retbleed/0026-x86-bugs-Report-Intel-retbleed-vulnerability.patch | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/debian/patches/bugfix/x86/retbleed/0026-x86-bugs-Report-Intel-retbleed-vulnerability.patch b/debian/patches/bugfix/x86/retbleed/0026-x86-bugs-Report-Intel-retbleed-vulnerability.patch new file mode 100644 index 000000000..d5f12f8d8 --- /dev/null +++ b/debian/patches/bugfix/x86/retbleed/0026-x86-bugs-Report-Intel-retbleed-vulnerability.patch @@ -0,0 +1,174 @@ +From: Peter Zijlstra <peterz@infradead.org> +Date: Fri, 24 Jun 2022 13:48:58 +0200 +Subject: x86/bugs: Report Intel retbleed vulnerability +Origin: https://git.kernel.org/linus/6ad0ad2bf8a67e27d1f9d006a1dabb0e1c360cc3 + +Skylake suffers from RSB underflow speculation issues; report this +vulnerability and it's mitigation (spectre_v2=ibrs). + + [jpoimboe: cleanups, eibrs] + +Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> +Signed-off-by: Borislav Petkov <bp@suse.de> +Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> +Signed-off-by: Borislav Petkov <bp@suse.de> +--- + arch/x86/include/asm/msr-index.h | 1 + + arch/x86/kernel/cpu/bugs.c | 39 +++++++++++++++++++++++++++----- + arch/x86/kernel/cpu/common.c | 24 ++++++++++---------- + 3 files changed, 46 insertions(+), 18 deletions(-) + +diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h +index d27e0581b777..059c7e500ab4 100644 +--- a/arch/x86/include/asm/msr-index.h ++++ b/arch/x86/include/asm/msr-index.h +@@ -93,6 +93,7 @@ + #define MSR_IA32_ARCH_CAPABILITIES 0x0000010a + #define ARCH_CAP_RDCL_NO BIT(0) /* Not susceptible to Meltdown */ + #define ARCH_CAP_IBRS_ALL BIT(1) /* Enhanced IBRS support */ ++#define ARCH_CAP_RSBA BIT(2) /* RET may use alternative branch predictors */ + #define ARCH_CAP_SKIP_VMENTRY_L1DFLUSH BIT(3) /* Skip L1D flush on vmentry */ + #define ARCH_CAP_SSB_NO BIT(4) /* + * Not susceptible to Speculative Store Bypass +diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c +index c546a9e4ed17..05f29db9473b 100644 +--- a/arch/x86/kernel/cpu/bugs.c ++++ b/arch/x86/kernel/cpu/bugs.c +@@ -790,12 +790,17 @@ static int __init nospectre_v1_cmdline(char *str) + } + early_param("nospectre_v1", nospectre_v1_cmdline); + ++static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init = ++ SPECTRE_V2_NONE; ++ + #undef pr_fmt + #define pr_fmt(fmt) "RETBleed: " fmt + + enum retbleed_mitigation { + RETBLEED_MITIGATION_NONE, + RETBLEED_MITIGATION_UNRET, ++ RETBLEED_MITIGATION_IBRS, ++ RETBLEED_MITIGATION_EIBRS, + }; + + enum retbleed_mitigation_cmd { +@@ -807,6 +812,8 @@ enum retbleed_mitigation_cmd { + const char * const retbleed_strings[] = { + [RETBLEED_MITIGATION_NONE] = "Vulnerable", + [RETBLEED_MITIGATION_UNRET] = "Mitigation: untrained return thunk", ++ [RETBLEED_MITIGATION_IBRS] = "Mitigation: IBRS", ++ [RETBLEED_MITIGATION_EIBRS] = "Mitigation: Enhanced IBRS", + }; + + static enum retbleed_mitigation retbleed_mitigation __ro_after_init = +@@ -849,6 +856,7 @@ early_param("retbleed", retbleed_parse_cmdline); + + #define RETBLEED_UNTRAIN_MSG "WARNING: BTB untrained return thunk mitigation is only effective on AMD/Hygon!\n" + #define RETBLEED_COMPILER_MSG "WARNING: kernel not compiled with RETPOLINE or -mfunction-return capable compiler!\n" ++#define RETBLEED_INTEL_MSG "WARNING: Spectre v2 mitigation leaves CPU vulnerable to RETBleed attacks, data leaks possible!\n" + + static void __init retbleed_select_mitigation(void) + { +@@ -865,12 +873,15 @@ static void __init retbleed_select_mitigation(void) + + case RETBLEED_CMD_AUTO: + default: +- if (!boot_cpu_has_bug(X86_BUG_RETBLEED)) +- break; +- + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD || + boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) + retbleed_mitigation = RETBLEED_MITIGATION_UNRET; ++ ++ /* ++ * The Intel mitigation (IBRS) was already selected in ++ * spectre_v2_select_mitigation(). ++ */ ++ + break; + } + +@@ -900,15 +911,31 @@ static void __init retbleed_select_mitigation(void) + break; + } + ++ /* ++ * Let IBRS trump all on Intel without affecting the effects of the ++ * retbleed= cmdline option. ++ */ ++ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) { ++ switch (spectre_v2_enabled) { ++ case SPECTRE_V2_IBRS: ++ retbleed_mitigation = RETBLEED_MITIGATION_IBRS; ++ break; ++ case SPECTRE_V2_EIBRS: ++ case SPECTRE_V2_EIBRS_RETPOLINE: ++ case SPECTRE_V2_EIBRS_LFENCE: ++ retbleed_mitigation = RETBLEED_MITIGATION_EIBRS; ++ break; ++ default: ++ pr_err(RETBLEED_INTEL_MSG); ++ } ++ } ++ + pr_info("%s\n", retbleed_strings[retbleed_mitigation]); + } + + #undef pr_fmt + #define pr_fmt(fmt) "Spectre V2 : " fmt + +-static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init = +- SPECTRE_V2_NONE; +- + static enum spectre_v2_user_mitigation spectre_v2_user_stibp __ro_after_init = + SPECTRE_V2_USER_NONE; + static enum spectre_v2_user_mitigation spectre_v2_user_ibpb __ro_after_init = +diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c +index 4089c173c6ae..75a5c720c852 100644 +--- a/arch/x86/kernel/cpu/common.c ++++ b/arch/x86/kernel/cpu/common.c +@@ -1237,24 +1237,24 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = { + VULNBL_INTEL_STEPPINGS(BROADWELL_G, X86_STEPPING_ANY, SRBDS), + VULNBL_INTEL_STEPPINGS(BROADWELL_X, X86_STEPPING_ANY, MMIO), + VULNBL_INTEL_STEPPINGS(BROADWELL, X86_STEPPING_ANY, SRBDS), +- VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPINGS(0x3, 0x3), SRBDS | MMIO), ++ VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPINGS(0x3, 0x3), SRBDS | MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPING_ANY, SRBDS), + VULNBL_INTEL_STEPPINGS(SKYLAKE_X, BIT(3) | BIT(4) | BIT(6) | +- BIT(7) | BIT(0xB), MMIO), +- VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPINGS(0x3, 0x3), SRBDS | MMIO), ++ BIT(7) | BIT(0xB), MMIO | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPINGS(0x3, 0x3), SRBDS | MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPING_ANY, SRBDS), +- VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPINGS(0x9, 0xC), SRBDS | MMIO), ++ VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPINGS(0x9, 0xC), SRBDS | MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPINGS(0x0, 0x8), SRBDS), +- VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPINGS(0x9, 0xD), SRBDS | MMIO), ++ VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPINGS(0x9, 0xD), SRBDS | MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPINGS(0x0, 0x8), SRBDS), +- VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPINGS(0x5, 0x5), MMIO | MMIO_SBDS), ++ VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPINGS(0x5, 0x5), MMIO | MMIO_SBDS | RETBLEED), + VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPINGS(0x1, 0x1), MMIO), + VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPINGS(0x4, 0x6), MMIO), +- VULNBL_INTEL_STEPPINGS(COMETLAKE, BIT(2) | BIT(3) | BIT(5), MMIO | MMIO_SBDS), +- VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS), +- VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x0, 0x0), MMIO), +- VULNBL_INTEL_STEPPINGS(LAKEFIELD, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS), +- VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPINGS(0x1, 0x1), MMIO), ++ VULNBL_INTEL_STEPPINGS(COMETLAKE, BIT(2) | BIT(3) | BIT(5), MMIO | MMIO_SBDS | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x0, 0x0), MMIO | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(LAKEFIELD, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPINGS(0x1, 0x1), MMIO | RETBLEED), + VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS), + VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D, X86_STEPPING_ANY, MMIO), + VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPINGS(0x0, 0x0), MMIO | MMIO_SBDS), +@@ -1364,7 +1364,7 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) + !arch_cap_mmio_immune(ia32_cap)) + setup_force_cpu_bug(X86_BUG_MMIO_STALE_DATA); + +- if (cpu_matches(cpu_vuln_blacklist, RETBLEED)) ++ if ((cpu_matches(cpu_vuln_blacklist, RETBLEED) || (ia32_cap & ARCH_CAP_RSBA))) + setup_force_cpu_bug(X86_BUG_RETBLEED); + + if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN)) |