net: Make copy_safe_from_sockptr() match documentation

commit eb94b7b upstream. copy_safe_from_sockptr() return copy_from_sockptr() return copy_from_sockptr_offset() return copy_from_user() copy_from_user() does not return an error on fault. Instead, it returns a number of bytes that were not copied. Have it handled. Patch has a side effect: it un-breaks garbage input handling of nfc_llcp_setsockopt() and mISDN's data_sock_setsockopt(). Fixes: 6309863 ("net: add copy_safe_from_sockptr() helper") Signed-off-by: Michal Luczaj <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w · Nov 22, 2024 · a0b8fd3 · a0b8fd3
1 parent 9b242c4
commit a0b8fd3
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
@@ -77,7 +77,9 @@ static inline int copy_safe_from_sockptr(void *dst, size_t ksize,
 {
 	if (optlen < ksize)
 		return -EINVAL;
-	return copy_from_sockptr(dst, optval, ksize);
+	if (copy_from_sockptr(dst, optval, ksize))
+		return -EFAULT;
+	return 0;
 }
 
 static inline int copy_to_sockptr_offset(sockptr_t dst, size_t offset,