[PATCH] afs: Fix check for NULL terminator

[David Howells]

From: Leo Stone <leocstone@xxxxxxxxx>
    
Add a missing check for reaching the end of the string while attempting
to split a command.

Fixes: f94f70d39cc2 ("afs: Provide a way to configure address priorities")
Reported-by: syzbot+7741f872f3c53385a2e2@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=7741f872f3c53385a2e2
Signed-off-by: Leo Stone <leocstone@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
---
 fs/afs/addr_prefs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/afs/addr_prefs.c b/fs/afs/addr_prefs.c
index c0384201b8fe..133736412c3d 100644
--- a/fs/afs/addr_prefs.c
+++ b/fs/afs/addr_prefs.c
@@ -48,7 +48,7 @@ static int afs_split_string(char **pbuf, char *strv[], unsigned int maxstrv)
 		strv[count++] = p;
 
 		/* Skip over word */
-		while (!isspace(*p))
+		while (!isspace(*p) && *p)
 			p++;
 		if (!*p)
 			break;