diff options
Diffstat (limited to 'arch/powerpc/mm/fault.c')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 01b9bcc7fa85..c448ca75f4b3 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -342,9 +342,20 @@ static inline void cmo_account_page_fault(void) { } #endif /* CONFIG_PPC_SMLPAR */ #ifdef CONFIG_PPC_BOOK3S -static void sanity_check_fault(bool is_write, unsigned long error_code) +static void sanity_check_fault(bool is_write, bool is_user, + unsigned long error_code, unsigned long address) { /* + * Userspace trying to access kernel address, we get PROTFAULT for that. + */ + if (is_user && address >= TASK_SIZE) { + pr_crit_ratelimited("%s[%d]: User access of kernel address (%lx) - exploit attempt? (uid: %d)\n", + current->comm, current->pid, address, + from_kuid(&init_user_ns, current_uid())); + return; + } + + /* * For hash translation mode, we should never get a * PROTFAULT. Any update to pte to reduce access will result in us * removing the hash page table entry, thus resulting in a DSISR_NOHPTE @@ -373,11 +384,14 @@ static void sanity_check_fault(bool is_write, unsigned long error_code) * For radix, we can get prot fault for autonuma case, because radix * page table will have them marked noaccess for user. */ - if (!radix_enabled() && !is_write) - WARN_ON_ONCE(error_code & DSISR_PROTFAULT); + if (radix_enabled() || is_write) + return; + + WARN_ON_ONCE(error_code & DSISR_PROTFAULT); } #else -static void sanity_check_fault(bool is_write, unsigned long error_code) { } +static void sanity_check_fault(bool is_write, bool is_user, + unsigned long error_code, unsigned long address) { } #endif /* CONFIG_PPC_BOOK3S */ /* @@ -435,7 +449,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, } /* Additional sanity check(s) */ - sanity_check_fault(is_write, error_code); + sanity_check_fault(is_write, is_user, error_code, address); /* * The kernel should never take an execute fault nor should it |