selinux: Add __GFP_NOWARN to allocation at str_read()

Tetsuo Handa · pcmoore · commit 4458bba09788 · 2018-09-13T15:36:25.000-04:00
syzbot is hitting warning at str_read() [1] because len parameter can become larger than KMALLOC_MAX_SIZE. We don't need to emit warning for this case. [1] https://syzkaller.appspot.com/bug?id=7f2f5aad79ea8663c296a2eedb81978401a908f0 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+ac488b9811036cea7ea0@syzkaller.appspotmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
@@ -1101,7 +1101,7 @@ static int str_read(char **strp, gfp_t flags, void *fp, u32 len)
 	if ((len == 0) || (len == (u32)-1))
 		return -EINVAL;
 
-	str = kmalloc(len + 1, flags);
+	str = kmalloc(len + 1, flags | __GFP_NOWARN);
 	if (!str)
 		return -ENOMEM;
 
