Commit 1c90ed1f authored by Thorsten Blum's avatar Thorsten Blum Committed by John Johansen
Browse files

apparmor: Replace deprecated strcpy with memcpy in gen_symlink_name 

strcpy() is deprecated; use memcpy() instead. Unlike strcpy(), memcpy()
does not copy the NUL terminator from the source string, which would be
overwritten anyway on every iteration when using strcpy(). snprintf()
then ensures that 'char *s' is NUL-terminated.

Replace the hard-coded path length to remove the magic number 6, and add
a comment explaining the extra 11 bytes.

Closes: https://github.com/KSPP/linux/issues/88


Signed-off-by: default avatarThorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: default avatarJohn Johansen <john.johansen@canonical.com>
parent 00b67657

security/apparmor/apparmorfs.c

+8 −4
Original line number Diff line number Diff line
@@ -1607,16 +1607,20 @@ static char *gen_symlink_name(int depth, const char *dirname, const char *fname) 
{

	char *buffer, *s;

	int error;

	int size = depth * 6 + strlen(dirname) + strlen(fname) + 11;

	const char *path = "../../";

	size_t path_len = strlen(path);

	int size;



	/* Extra 11 bytes: "raw_data" (9) + two slashes "//" (2) */

	size = depth * path_len + strlen(dirname) + strlen(fname) + 11;

	s = buffer = kmalloc(size, GFP_KERNEL);

	if (!buffer)

		return ERR_PTR(-ENOMEM);



	for (; depth > 0; depth--) {

		strcpy(s, "../../");

		s += 6;

		size -= 6;

		memcpy(s, path, path_len);

		s += path_len;

		size -= path_len;

	}



	error = snprintf(s, size, "raw_data/%s/%s", dirname, fname);