From 607566aeccde6ffccde5eef173ed0d277eec4a2d Mon Sep 17 00:00:00 2001 From: Josh Boyer Date: Fri, 20 Sep 2013 14:17:52 +0100 Subject: [PATCH] CacheFiles: Fix memory leak in cachefiles_check_auxdata error paths In cachefiles_check_auxdata(), we allocate auxbuf but fail to free it if we determine there's an error or that the data is stale. Further, assigning the output of vfs_getxattr() to auxbuf->len gives problems with checking for errors as auxbuf->len is a u16. We don't actually need to set auxbuf->len, so keep the length in a variable for now. We shouldn't need to check the upper limit of the buffer as an overflow there should be indicated by -ERANGE. While we're at it, fscache_check_aux() returns an enum value, not an int, so assign it to an appropriately typed variable rather than to ret. Signed-off-by: Josh Boyer Signed-off-by: David Howells cc: Hongyi Jia cc: Milosz Tanski Signed-off-by: Linus Torvalds --- fs/cachefiles/xattr.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c index 34c88b83e39f..12b0eef84183 100644 --- a/fs/cachefiles/xattr.c +++ b/fs/cachefiles/xattr.c @@ -162,8 +162,9 @@ int cachefiles_update_object_xattr(struct cachefiles_object *object, int cachefiles_check_auxdata(struct cachefiles_object *object) { struct cachefiles_xattr *auxbuf; + enum fscache_checkaux validity; struct dentry *dentry = object->dentry; - unsigned int dlen; + ssize_t xlen; int ret; ASSERT(dentry); @@ -174,22 +175,22 @@ int cachefiles_check_auxdata(struct cachefiles_object *object) if (!auxbuf) return -ENOMEM; - auxbuf->len = vfs_getxattr(dentry, cachefiles_xattr_cache, - &auxbuf->type, 512 + 1); - if (auxbuf->len < 1) - return -ESTALE; - - if (auxbuf->type != object->fscache.cookie->def->type) - return -ESTALE; + xlen = vfs_getxattr(dentry, cachefiles_xattr_cache, + &auxbuf->type, 512 + 1); + ret = -ESTALE; + if (xlen < 1 || + auxbuf->type != object->fscache.cookie->def->type) + goto error; - dlen = auxbuf->len - 1; - ret = fscache_check_aux(&object->fscache, &auxbuf->data, dlen); + xlen--; + validity = fscache_check_aux(&object->fscache, &auxbuf->data, xlen); + if (validity != FSCACHE_CHECKAUX_OKAY) + goto error; + ret = 0; +error: kfree(auxbuf); - if (ret != FSCACHE_CHECKAUX_OKAY) - return -ESTALE; - - return 0; + return ret; } /* -- GitLab