[PATCH, v4] vfs: introduce helper function to safely NUL-terminate symlinks

[Duane Griffin]

A number of filesystems were potentially triggering kernel bugs due to
corrupted symlink names on disk. This helper helps safely terminate the
names.

Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Duane Griffin <duaneg@xxxxxxxxx>
---

Version 4, this time with size_t instead of unsigned. Thanks Al!

 include/linux/namei.h |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/include/linux/namei.h b/include/linux/namei.h
index 99eb803..231ce28 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -94,4 +94,9 @@ static inline char *nd_get_link(struct nameidata *nd)
 	return nd->saved_names[nd->depth];
 }
 
+static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
+{
+	((char *) name)[min(len, maxlen)] = '\0';
+}
+
 #endif /* _LINUX_NAMEI_H */
-- 
1.6.0.4

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