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authorJisheng Zhang <jszhang@kernel.org>2022-10-29 14:34:50 +0300
committerPalmer Dabbelt <palmer@rivosinc.com>2022-11-11 00:43:15 +0300
commit6510c78490c490a6636e48b61eeaa6fb65981f4b (patch)
tree65dc7264deb011465dd3ec3e3040e49f7cfe6669
parent8bc8824d30193eb7755043d5bb65fa7f0d11a595 (diff)
downloadlinux-6510c78490c490a6636e48b61eeaa6fb65981f4b.tar.xz
riscv: process: fix kernel info leakage
thread_struct's s[12] may contain random kernel memory content, which may be finally leaked to userspace. This is a security hole. Fix it by clearing the s[12] array in thread_struct when fork. As for kthread case, it's better to clear the s[12] array as well. Fixes: 7db91e57a0ac ("RISC-V: Task implementation") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Tested-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20221029113450.4027-1-jszhang@kernel.org Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/CAJF2gTSdVyAaM12T%2B7kXAdRPGS4VyuO08X1c7paE-n4Fr8OtRA@mail.gmail.com/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r--arch/riscv/kernel/process.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index b0c63e8e867e..8955f2432c2d 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -164,6 +164,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
unsigned long tls = args->tls;
struct pt_regs *childregs = task_pt_regs(p);
+ memset(&p->thread.s, 0, sizeof(p->thread.s));
+
/* p->thread holds context to be restored by __switch_to() */
if (unlikely(args->fn)) {
/* Kernel thread */