[PATCH -next] riscv: Implement thread_struct whitelist for hardened usercopy
From: Tong Tiangen <hidden>
Date: 2021-07-02 04:46:27
Also in:
lkml
Subsystem:
risc-v architecture, the rest · Maintainers:
Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
This whitelists the FPU register state portion of the thread_struct for copying to userspace, instead of the default entire struct. Signed-off-by: Tong Tiangen <redacted> --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/processor.h | 8 ++++++++ 2 files changed, 9 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 821081bdb8b8..5c26c0726944 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig@@ -70,6 +70,7 @@ config RISCV select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK + select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ASM_MODVERSIONS select HAVE_CONTEXT_TRACKING select HAVE_DEBUG_KMEMLEAK
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 021ed64ee608..46b492c78cbb 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h@@ -37,6 +37,14 @@ struct thread_struct { unsigned long bad_cause; }; +/* Whitelist the fstate from the task_struct for hardened usercopy */ +static inline void arch_thread_struct_whitelist(unsigned long *offset, + unsigned long *size) +{ + *offset = offsetof(struct thread_struct, fstate); + *size = sizeof_field(struct thread_struct, fstate); +} + #define INIT_THREAD { \ .sp = sizeof(init_stack) + (long)&init_stack, \ }
--
2.25.1
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