diff options
| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2019-04-18 16:51:19 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2019-04-21 23:05:56 +1000 |
| commit | 0fb1c25ab523614b056ace11be67aac8f8ccabb1 (patch) | |
| tree | 0f458e2ca41b6e94626f1d7bc41c4557e42a44ec | |
| parent | powerpc: Add framework for Kernel Userspace Protection (diff) | |
| download | linux-dev-0fb1c25ab523614b056ace11be67aac8f8ccabb1.tar.xz linux-dev-0fb1c25ab523614b056ace11be67aac8f8ccabb1.zip | |
powerpc: Add skeleton for Kernel Userspace Execution Prevention
This patch adds a skeleton for Kernel Userspace Execution Prevention.
Then subarches implementing it have to define CONFIG_PPC_HAVE_KUEP
and provide setup_kuep() function.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Don't split strings, use pr_crit_ratelimited()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kup.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/mm/fault.c | 9 | ||||
| -rw-r--r-- | arch/powerpc/mm/init-common.c | 11 | ||||
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 12 |
5 files changed, 34 insertions, 6 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2b8ee90bb644..a53df74589e5 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2843,7 +2843,7 @@ Disable SMAP (Supervisor Mode Access Prevention) even if it is supported by processor. - nosmep [X86] + nosmep [X86,PPC] Disable SMEP (Supervisor Mode Execution Prevention) even if it is supported by processor. diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h index 7a88b8b9b54d..a2a959cb4e36 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -6,6 +6,12 @@ void setup_kup(void); +#ifdef CONFIG_PPC_KUEP +void setup_kuep(bool disabled); +#else +static inline void setup_kuep(bool disabled) { } +#endif /* CONFIG_PPC_KUEP */ + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_KUP_H_ */ diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 887f11bcf330..3384354abc1d 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -229,11 +229,10 @@ static bool bad_kernel_fault(bool is_exec, unsigned long error_code, /* NX faults set DSISR_PROTFAULT on the 8xx, DSISR_NOEXEC_OR_G on others */ if (is_exec && (error_code & (DSISR_NOEXEC_OR_G | DSISR_KEYFAULT | DSISR_PROTFAULT))) { - printk_ratelimited(KERN_CRIT "kernel tried to execute" - " exec-protected page (%lx) -" - "exploit attempt? (uid: %d)\n", - address, from_kuid(&init_user_ns, - current_uid())); + pr_crit_ratelimited("kernel tried to execute %s page (%lx) - exploit attempt? (uid: %d)\n", + address >= TASK_SIZE ? "exec-protected" : "user", + address, + from_kuid(&init_user_ns, current_uid())); } return is_exec || (address >= TASK_SIZE); } diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c index 36d28e872289..83f95a5565d6 100644 --- a/arch/powerpc/mm/init-common.c +++ b/arch/powerpc/mm/init-common.c @@ -26,8 +26,19 @@ #include <asm/pgtable.h> #include <asm/kup.h> +static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); + +static int __init parse_nosmep(char *p) +{ + disable_kuep = true; + pr_warn("Disabling Kernel Userspace Execution Prevention\n"); + return 0; +} +early_param("nosmep", parse_nosmep); + void __init setup_kup(void) { + setup_kuep(disable_kuep); } #define CTOR(shift) static void ctor_##shift(void *addr) \ diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 842b2c7e156a..7d30bbbaa3c1 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -345,6 +345,18 @@ config PPC_RADIX_MMU_DEFAULT If you're unsure, say Y. +config PPC_HAVE_KUEP + bool + +config PPC_KUEP + bool "Kernel Userspace Execution Prevention" + depends on PPC_HAVE_KUEP + default y + help + Enable support for Kernel Userspace Execution Prevention (KUEP) + + If you're unsure, say Y. + config ARCH_ENABLE_HUGEPAGE_MIGRATION def_bool y depends on PPC_BOOK3S_64 && HUGETLB_PAGE && MIGRATION |