metag/ptrace: Reject partial NT_METAG_RPIPE writes

It's not clear what behaviour is sensible when doing partial write of NT_METAG_RPIPE, so just don't bother. This patch assumes that userspace will never rely on a partial SETREGSET in this case, since it's not clear what should happen anyway. Signed-off-by: Dave Martin <[email protected]> Acked-by: James Hogan <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mrcsosa · Mar 29, 2017 · 7195ee3 · 7195ee3
1 parent 5fe81fe
commit 7195ee3
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/arch/metag/kernel/ptrace.c b/arch/metag/kernel/ptrace.c
@@ -253,6 +253,8 @@ int metag_rp_state_copyin(struct pt_regs *regs,
 	unsigned long long *ptr;
 	int ret, i;
 
+	if (count < 4*13)
+		return -EINVAL;
 	/* Read the entire pipeline before making any changes */
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 				 &rp, 0, 4*13);