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| author | Kees Cook <keescook@chromium.org> | 2017-08-16 14:09:13 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2018-01-15 12:08:06 -0800 |
| commit | 08626a6056aad824c43d34ce587ab2b01f49d1a4 (patch) | |
| tree | cbf024b04979925f657fb5fead7d10edac2efbe7 /arch | |
| parent | 9e8084d3f761413b2d58b2625bc6e332eab2bfce (diff) | |
| download | linux-08626a6056aad824c43d34ce587ab2b01f49d1a4.tar.gz linux-08626a6056aad824c43d34ce587ab2b01f49d1a4.tar.bz2 linux-08626a6056aad824c43d34ce587ab2b01f49d1a4.zip | |
arm: Implement thread_struct whitelist for hardened usercopy
While ARM32 carries FPU state in the thread structure that is saved and
restored during signal handling, it doesn't need to declare a usercopy
whitelist, since existing accessors are all either using a bounce buffer
(for which whitelisting isn't checking the slab), are statically sized
(which will bypass the hardened usercopy check), or both.
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/processor.h | 10 |
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 51c8df561077..3ea00d65f35d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -50,6 +50,7 @@ config ARM select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) + select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK select HAVE_ARM_SMCCC if CPU_V7 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32 diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index 338cbe0a18ef..1bf65b47808a 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -45,6 +45,16 @@ struct thread_struct { struct debug_info debug; }; +/* + * Everything usercopied to/from thread_struct is statically-sized, so + * no hardened usercopy whitelist is needed. + */ +static inline void arch_thread_struct_whitelist(unsigned long *offset, + unsigned long *size) +{ + *offset = *size = 0; +} + #define INIT_THREAD { } #define start_thread(regs,pc,sp) \ |