From: Roberto Sassu roberto.sassu@huawei.com
commit d82dcd9e21b77d338dc4875f3d4111f0db314a7c upstream.
Reiserfs sets a security xattr at inode creation time in two stages: first, it calls reiserfs_security_init() to obtain the xattr from active LSMs; then, it calls reiserfs_security_write() to actually write that xattr.
Unfortunately, it seems there is a wrong expectation that LSMs provide the full xattr name in the form 'security.<suffix>'. However, LSMs always provided just the suffix, causing reiserfs to not write the xattr at all (if the suffix is shorter than the prefix), or to write an xattr with the wrong name.
Add a temporary buffer in reiserfs_security_write(), and write to it the full xattr name, before passing it to reiserfs_xattr_set_handle().
Also replace the name length check with a check that the full xattr name is not larger than XATTR_NAME_MAX.
Cc: stable@vger.kernel.org # v2.6.x Fixes: 57fe60df6241 ("reiserfs: add atomic addition of selinux attributes during inode creation") Signed-off-by: Roberto Sassu roberto.sassu@huawei.com Signed-off-by: Paul Moore paul@paul-moore.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/reiserfs/xattr_security.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/fs/reiserfs/xattr_security.c +++ b/fs/reiserfs/xattr_security.c @@ -82,11 +82,15 @@ int reiserfs_security_write(struct reise struct inode *inode, struct reiserfs_security_handle *sec) { + char xattr_name[XATTR_NAME_MAX + 1] = XATTR_SECURITY_PREFIX; int error; - if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX)) + + if (XATTR_SECURITY_PREFIX_LEN + strlen(sec->name) > XATTR_NAME_MAX) return -EINVAL;
- error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value, + strlcat(xattr_name, sec->name, sizeof(xattr_name)); + + error = reiserfs_xattr_set_handle(th, inode, xattr_name, sec->value, sec->length, XATTR_CREATE); if (error == -ENODATA || error == -EOPNOTSUPP) error = 0;