riscv: misaligned: Restrict user access to kernel memory

raw_copy_{to,from}_user() do not call access_ok(), so this code allowed
userspace to access any virtual memory address.

Cc: stable@vger.kernel.org
Fixes: 7c83232161f6 ("riscv: add support for misaligned trap handling in S-mode")
Fixes: 441381506ba7 ("riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240815005714.1163136-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c
index 192cd5603e95f9b92211cb616b98df7c6bc602d9..d4fd8af7aaf5a937de9c3f50f0d52cd51f845645 100644 (file)
--- a/arch/riscv/kernel/traps_misaligned.c
+++ b/arch/riscv/kernel/traps_misaligned.c
@@ -417,7 +417,7 @@ int handle_misaligned_load(struct pt_regs *regs)
 
        val.data_u64 = 0;
        if (user_mode(regs)) {
-               if (raw_copy_from_user(&val, (u8 __user *)addr, len))
+               if (copy_from_user(&val, (u8 __user *)addr, len))
                        return -1;
        } else {
                memcpy(&val, (u8 *)addr, len);
@@ -515,7 +515,7 @@ int handle_misaligned_store(struct pt_regs *regs)
                return -EOPNOTSUPP;
 
        if (user_mode(regs)) {
-               if (raw_copy_to_user((u8 __user *)addr, &val, len))
+               if (copy_to_user((u8 __user *)addr, &val, len))
                        return -1;
        } else {
                memcpy((u8 *)addr, &val, len);