diff options
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/kup.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kup.h | 34 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kup.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/nohash/32/kup-8xx.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/mm/fault.c | 4 |
5 files changed, 25 insertions, 25 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index b18cd931e325..32fd4452e960 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -177,8 +177,8 @@ static inline void restore_user_access(unsigned long flags) allow_user_access(to, to, end - addr, KUAP_READ_WRITE); } -static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address, - bool is_write, unsigned long error_code) +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { unsigned long begin = regs->kuap & 0xf0000000; unsigned long end = regs->kuap << 28; diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h index f2e6dd78d5e2..7075c92c320c 100644 --- a/arch/powerpc/include/asm/book3s/64/kup.h +++ b/arch/powerpc/include/asm/book3s/64/kup.h @@ -353,29 +353,29 @@ static inline void set_kuap(unsigned long value) isync(); } -#define RADIX_KUAP_BLOCK_READ UL(0x4000000000000000) -#define RADIX_KUAP_BLOCK_WRITE UL(0x8000000000000000) - static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address, - bool is_write, unsigned long error_code) + bool is_write) { if (!mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) return false; - - if (radix_enabled()) { - /* - * Will be a storage protection fault. - * Only check the details of AMR[0] - */ - return WARN((regs->kuap & (is_write ? RADIX_KUAP_BLOCK_WRITE : RADIX_KUAP_BLOCK_READ)), - "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read"); - } /* - * We don't want to WARN here because userspace can setup - * keys such that a kernel access to user address can cause - * fault + * For radix this will be a storage protection fault (DSISR_PROTFAULT). + * For hash this will be a key fault (DSISR_KEYFAULT) */ - return !!(error_code & DSISR_KEYFAULT); + /* + * We do have exception table entry, but accessing the + * userspace results in fault. This could be because we + * didn't unlock the AMR or access is denied by userspace + * using a key value that blocks access. We are only interested + * in catching the use case of accessing without unlocking + * the AMR. Hence check for BLOCK_WRITE/READ against AMR. + */ + if (is_write) { + return WARN(((regs->amr & AMR_KUAP_BLOCK_WRITE) == AMR_KUAP_BLOCK_WRITE), + "Bug: Write fault blocked by AMR!"); + } + return WARN(((regs->amr & AMR_KUAP_BLOCK_READ) == AMR_KUAP_BLOCK_READ), + "Bug: Read fault blocked by AMR!"); } static __always_inline void allow_user_access(void __user *to, const void __user *from, diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h index f8ec679bd2de..5a9820c54da9 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -62,8 +62,8 @@ void setup_kuap(bool disabled); #else static inline void setup_kuap(bool disabled) { } -static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address, - bool is_write, unsigned long error_code) +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { return false; } diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h index 7bdd9e5b63ed..567cdc557402 100644 --- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h @@ -60,8 +60,8 @@ static inline void restore_user_access(unsigned long flags) mtspr(SPRN_MD_AP, flags); } -static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address, - bool is_write, unsigned long error_code) +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xff000000), "Bug: fault blocked by AP register !"); diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index c91621df0c61..b12595102525 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -210,7 +210,7 @@ static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code, return true; } - if (!is_exec && address < TASK_SIZE && (error_code & DSISR_PROTFAULT) && + if (!is_exec && address < TASK_SIZE && (error_code & (DSISR_PROTFAULT | DSISR_KEYFAULT)) && !search_exception_tables(regs->nip)) { pr_crit_ratelimited("Kernel attempted to access user page (%lx) - exploit attempt? (uid: %d)\n", address, @@ -227,7 +227,7 @@ static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code, // Read/write fault in a valid region (the exception table search passed // above), but blocked by KUAP is bad, it can never succeed. - if (bad_kuap_fault(regs, address, is_write, error_code)) + if (bad_kuap_fault(regs, address, is_write)) return true; // What's left? Kernel fault on user in well defined regions (extable |