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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 <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hongyi Jia <jiayisuse@gmail.com>
cc: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
master
Josh Boyer 8 years ago
committed by Linus Torvalds
parent
commit
607566aecc
  1. 29
      fs/cachefiles/xattr.c

29
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;
}
/*

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