__dentry_path() fixes
* we need to save the starting point for restarts
* reject pathologically short buffers outright
Spotted-by: Denys Vlasenko <dvlasenk@redhat.com>
Spotted-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/dcache.c b/fs/dcache.c
index fdbe230..265e0ce 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -3116,19 +3116,22 @@
/*
* Write full pathname from the root of the filesystem into the buffer.
*/
-static char *__dentry_path(struct dentry *dentry, char *buf, int buflen)
+static char *__dentry_path(struct dentry *d, char *buf, int buflen)
{
+ struct dentry *dentry;
char *end, *retval;
int len, seq = 0;
int error = 0;
+ if (buflen < 2)
+ goto Elong;
+
rcu_read_lock();
restart:
+ dentry = d;
end = buf + buflen;
len = buflen;
prepend(&end, &len, "\0", 1);
- if (buflen < 1)
- goto Elong;
/* Get '/' right */
retval = end-1;
*retval = '/';