fs/9p: avoid debug OOPS when reading a long symlink
Reading a symlink longer than the given buffer, a p9_debug use would
try to print the link name (not NUL-terminated) using a %s format.
Use %.*s instead, and replace the strncpy+strnlen with functionally
equivalent strlen+memcpy.
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index cbf9dbb..890bed5 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1276,12 +1276,12 @@
}
/* copy extension buffer into buffer */
- strncpy(buffer, st->extension, buflen);
+ retval = min(strlen(st->extension)+1, (size_t)buflen);
+ memcpy(buffer, st->extension, retval);
- p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n",
- dentry->d_name.name, st->extension, buffer);
+ p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n",
+ dentry->d_name.name, st->extension, buflen, buffer);
- retval = strnlen(buffer, buflen);
done:
p9stat_free(st);
kfree(st);