diff options
Diffstat (limited to 'arch/powerpc/mm/fault.c')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 215690452495..806c74e0d5ab 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -17,6 +17,7 @@ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/string.h> +#include <linux/string_choices.h> #include <linux/types.h> #include <linux/pagemap.h> #include <linux/ptrace.h> @@ -218,7 +219,7 @@ static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code, // Read/write fault blocked by KUAP is bad, it can never succeed. if (bad_kuap_fault(regs, address, is_write)) { pr_crit_ratelimited("Kernel attempted to %s user page (%lx) - exploit attempt? (uid: %d)\n", - is_write ? "write" : "read", address, + str_write_read(is_write), address, from_kuid(&init_user_ns, current_uid())); // Fault on user outside of certain regions (eg. copy_tofrom_user()) is bad @@ -368,13 +369,13 @@ static void sanity_check_fault(bool is_write, bool is_user, * Define the correct "is_write" bit in error_code based * on the processor family */ -#if (defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) +#ifdef CONFIG_BOOKE #define page_fault_is_write(__err) ((__err) & ESR_DST) #else #define page_fault_is_write(__err) ((__err) & DSISR_ISSTORE) #endif -#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) +#ifdef CONFIG_BOOKE #define page_fault_is_bad(__err) (0) #elif defined(CONFIG_PPC_8xx) #define page_fault_is_bad(__err) ((__err) & DSISR_NOEXEC_OR_G) @@ -439,10 +440,16 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, /* * The kernel should never take an execute fault nor should it * take a page fault to a kernel address or a page fault to a user - * address outside of dedicated places + * address outside of dedicated places. + * + * Rather than kfence directly reporting false negatives, search whether + * the NIP belongs to the fixup table for cases where fault could come + * from functions like copy_from_kernel_nofault(). */ if (unlikely(!is_user && bad_kernel_fault(regs, error_code, address, is_write))) { - if (kfence_handle_page_fault(address, is_write, regs)) + if (is_kfence_address((void *)address) && + !search_exception_tables(instruction_pointer(regs)) && + kfence_handle_page_fault(address, is_write, regs)) return 0; return SIGSEGV; @@ -619,7 +626,7 @@ static void __bad_page_fault(struct pt_regs *regs, int sig) case INTERRUPT_DATA_STORAGE: case INTERRUPT_H_DATA_STORAGE: pr_alert("BUG: %s on %s at 0x%08lx\n", msg, - is_write ? "write" : "read", regs->dar); + str_write_read(is_write), regs->dar); break; case INTERRUPT_DATA_SEGMENT: pr_alert("BUG: %s at 0x%08lx\n", msg, regs->dar); |