From: Joel Becker <[email protected]> commit 1fc8a117865b54590acd773a55fbac9221b018f0 upstream.
ocfs2 fast symlinks are NUL terminated strings stored inline in the inode data area. However, disk corruption or a local attacker could, in theory, remove that NUL. Because we're using strlen() (my fault, introduced in a731d1 when removing vfs_follow_link()), we could walk off the end of that string. Signed-off-by: Joel Becker <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- fs/ocfs2/symlink.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c index 32499d21..9975457 100644 --- a/fs/ocfs2/symlink.c +++ b/fs/ocfs2/symlink.c @@ -128,7 +128,7 @@ static void *ocfs2_fast_follow_link(struct dentry *dentry, } /* Fast symlinks can't be large */ - len = strlen(target); + len = strnlen(target, ocfs2_fast_symlink_chars(inode->i_sb)); link = kzalloc(len + 1, GFP_NOFS); if (!link) { status = -ENOMEM; -- 1.7.3.3 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
