diff options
Diffstat (limited to 'arch/arm64/include/asm/mman.h')
| -rw-r--r-- | arch/arm64/include/asm/mman.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h index 5966ee4a6154..6d4940342ba7 100644 --- a/arch/arm64/include/asm/mman.h +++ b/arch/arm64/include/asm/mman.h @@ -35,11 +35,40 @@ static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags) } #define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags) +static inline bool arm64_check_wx_prot(unsigned long prot, + struct task_struct *tsk) +{ + /* + * When we are running with SCTLR_ELx.WXN==1, writable mappings are + * implicitly non-executable. This means we should reject such mappings + * when user space attempts to create them using mmap() or mprotect(). + */ + if (arm64_wxn_enabled() && + ((prot & (PROT_WRITE | PROT_EXEC)) == (PROT_WRITE | PROT_EXEC))) { + /* + * User space libraries such as libffi carry elaborate + * heuristics to decide whether it is worth it to even attempt + * to create writable executable mappings, as PaX or selinux + * enabled systems will outright reject it. They will usually + * fall back to something else (e.g., two separate shared + * mmap()s of a temporary file) on failure. + */ + pr_info_ratelimited( + "process %s (%d) attempted to create PROT_WRITE+PROT_EXEC mapping\n", + tsk->comm, tsk->pid); + return false; + } + return true; +} + static inline bool arch_validate_prot(unsigned long prot, unsigned long addr __always_unused) { unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM; + if (!arm64_check_wx_prot(prot, current)) + return false; + if (system_supports_bti()) supported |= PROT_BTI; @@ -50,6 +79,13 @@ static inline bool arch_validate_prot(unsigned long prot, } #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr) +static inline bool arch_validate_mmap_prot(unsigned long prot, + unsigned long addr) +{ + return arm64_check_wx_prot(prot, current); +} +#define arch_validate_mmap_prot arch_validate_mmap_prot + static inline bool arch_validate_flags(unsigned long vm_flags) { if (!system_supports_mte()) |