From 2b68f6caeac271620cd2f9362aeaed360e317df0 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 14 Apr 2015 15:48:00 -0700 Subject: mm: expose arch_mmap_rnd when available When an architecture fully supports randomizing the ELF load location, a per-arch mmap_rnd() function is used to find a randomized mmap base. In preparation for randomizing the location of ET_DYN binaries separately from mmap, this renames and exports these functions as arch_mmap_rnd(). Additionally introduces CONFIG_ARCH_HAS_ELF_RANDOMIZE for describing this feature on architectures that support it (which is a superset of ARCH_BINFMT_ELF_RANDOMIZE_PIE, since s390 already supports a separated ET_DYN ASLR from mmap ASLR without the ARCH_BINFMT_ELF_RANDOMIZE_PIE logic). Signed-off-by: Kees Cook Cc: Hector Marco-Gisbert Cc: Russell King Reviewed-by: Ingo Molnar Cc: Catalin Marinas Cc: Will Deacon Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Alexander Viro Cc: Oleg Nesterov Cc: Andy Lutomirski Cc: "David A. Long" Cc: Andrey Ryabinin Cc: Arun Chandran Cc: Yann Droneaud Cc: Min-Hua Chen Cc: Paul Burton Cc: Alex Smith Cc: Markos Chandras Cc: Vineeth Vijayan Cc: Jeff Bailey Cc: Michael Holzheu Cc: Ben Hutchings Cc: Behan Webster Cc: Ismael Ripoll Cc: Jan-Simon Mller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/Kconfig | 7 +++++++ arch/arm/Kconfig | 1 + arch/arm/mm/mmap.c | 4 ++-- arch/arm64/Kconfig | 1 + arch/arm64/mm/mmap.c | 4 ++-- arch/mips/Kconfig | 1 + arch/mips/mm/mmap.c | 4 ++-- arch/powerpc/Kconfig | 1 + arch/powerpc/mm/mmap.c | 4 ++-- arch/s390/Kconfig | 1 + arch/s390/mm/mmap.c | 8 ++++---- arch/x86/Kconfig | 1 + arch/x86/mm/mmap.c | 4 ++-- include/linux/elf-randomize.h | 10 ++++++++++ 14 files changed, 37 insertions(+), 14 deletions(-) create mode 100644 include/linux/elf-randomize.h diff --git a/arch/Kconfig b/arch/Kconfig index c88c23f0a1da..474904a8e540 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -491,6 +491,13 @@ config PGTABLE_LEVELS int default 2 +config ARCH_HAS_ELF_RANDOMIZE + bool + help + An architecture supports choosing randomized locations for + stack, mmap, brk, and ET_DYN. Defined functions: + - arch_mmap_rnd() + # # ABI hall of shame # diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 696cf3c61e0f..f85200a63a8b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -3,6 +3,7 @@ config ARM default y select ARCH_BINFMT_ELF_RANDOMIZE_PIE select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE + select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAVE_CUSTOM_GPIO_H select ARCH_HAS_GCOV_PROFILE_ALL diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 15a8160096b3..407dc786583a 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -169,7 +169,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } -static unsigned long mmap_rnd(void) +unsigned long arch_mmap_rnd(void) { unsigned long rnd; @@ -184,7 +184,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) - random_factor = mmap_rnd(); + random_factor = arch_mmap_rnd(); if (mmap_is_legacy()) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3f2fba996bc2..7c1dbeb73e8d 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2,6 +2,7 @@ config ARM64 def_bool y select ARCH_BINFMT_ELF_RANDOMIZE_PIE select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE + select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_SG_CHAIN select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index ba776c01b552..ed177475dd8c 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -47,7 +47,7 @@ static int mmap_is_legacy(void) return sysctl_legacy_va_layout; } -static unsigned long mmap_rnd(void) +unsigned long arch_mmap_rnd(void) { unsigned long rnd; @@ -77,7 +77,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) - random_factor = mmap_rnd(); + random_factor = arch_mmap_rnd(); /* * Fall back to the standard layout if the personality bit is set, or diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index a9d112d2a135..688ce274f59d 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -24,6 +24,7 @@ config MIPS select HAVE_DEBUG_KMEMLEAK select HAVE_SYSCALL_TRACEPOINTS select ARCH_BINFMT_ELF_RANDOMIZE_PIE + select ARCH_HAS_ELF_RANDOMIZE select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES && 64BIT select RTC_LIB if !MACH_LOONGSON select GENERIC_ATOMIC64 if !64BIT diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index 9a4f1f5c1f0e..5c81fdd032c3 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -142,7 +142,7 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, addr0, len, pgoff, flags, DOWN); } -static unsigned long mmap_rnd(void) +unsigned long arch_mmap_rnd(void) { unsigned long rnd; @@ -161,7 +161,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) - random_factor = mmap_rnd(); + random_factor = arch_mmap_rnd(); if (mmap_is_legacy()) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 91ad76f30d18..fc5fffbb331b 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -89,6 +89,7 @@ config PPC select ARCH_MIGHT_HAVE_PC_SERIO select BINFMT_ELF select ARCH_BINFMT_ELF_RANDOMIZE_PIE + select ARCH_HAS_ELF_RANDOMIZE select OF select OF_EARLY_FLATTREE select OF_RESERVED_MEM diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c index 1ad2299d795d..0f0502e12f6c 100644 --- a/arch/powerpc/mm/mmap.c +++ b/arch/powerpc/mm/mmap.c @@ -53,7 +53,7 @@ static inline int mmap_is_legacy(void) return sysctl_legacy_va_layout; } -static unsigned long mmap_rnd(void) +unsigned long arch_mmap_rnd(void) { unsigned long rnd; @@ -87,7 +87,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) - random_factor = mmap_rnd(); + random_factor = arch_mmap_rnd(); /* * Fall back to the standard layout if the personality diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index f6aebcb7a0f8..ac2b75d74cd2 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -65,6 +65,7 @@ config S390 def_bool y select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS + select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_SG_CHAIN select ARCH_HAVE_NMI_SAFE_CMPXCHG diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c index db57078075c5..a94504d99c47 100644 --- a/arch/s390/mm/mmap.c +++ b/arch/s390/mm/mmap.c @@ -60,7 +60,7 @@ static inline int mmap_is_legacy(void) return sysctl_legacy_va_layout; } -static unsigned long mmap_rnd(void) +unsigned long arch_mmap_rnd(void) { if (is_32bit_task()) return (get_random_int() & 0x7ff) << PAGE_SHIFT; @@ -187,7 +187,7 @@ unsigned long randomize_et_dyn(void) base &= ~((1UL << 32) - 1); if (current->flags & PF_RANDOMIZE) - base += mmap_rnd(); + base += arch_mmap_rnd(); return base; } @@ -203,7 +203,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) - random_factor = mmap_rnd(); + random_factor = arch_mmap_rnd(); /* * Fall back to the standard layout if the personality @@ -283,7 +283,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) - random_factor = mmap_rnd(); + random_factor = arch_mmap_rnd(); /* * Fall back to the standard layout if the personality diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0f948cefaeb1..782ddbbc1c9a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -88,6 +88,7 @@ config X86 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP select HAVE_USER_RETURN_NOTIFIER select ARCH_BINFMT_ELF_RANDOMIZE_PIE + select ARCH_HAS_ELF_RANDOMIZE select HAVE_ARCH_JUMP_LABEL select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select SPARSE_IRQ diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index ebfa52030d5c..9d518d693b4b 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -65,7 +65,7 @@ static int mmap_is_legacy(void) return sysctl_legacy_va_layout; } -static unsigned long mmap_rnd(void) +unsigned long arch_mmap_rnd(void) { unsigned long rnd; @@ -114,7 +114,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) - random_factor = mmap_rnd(); + random_factor = arch_mmap_rnd(); mm->mmap_legacy_base = mmap_legacy_base(random_factor); diff --git a/include/linux/elf-randomize.h b/include/linux/elf-randomize.h new file mode 100644 index 000000000000..7a4eda02d2b1 --- /dev/null +++ b/include/linux/elf-randomize.h @@ -0,0 +1,10 @@ +#ifndef _ELF_RANDOMIZE_H +#define _ELF_RANDOMIZE_H + +#ifndef CONFIG_ARCH_HAS_ELF_RANDOMIZE +static inline unsigned long arch_mmap_rnd(void) { return 0; } +#else +extern unsigned long arch_mmap_rnd(void); +#endif + +#endif -- cgit v1.2.3