nfsd4: fix acl buffer overrun
4ac7249ea5a0ceef9f8269f63f33cc873c3fac61 "nfsd: use get_acl and
->set_acl" forgets to set the size in the case get_acl() succeeds, so
_posix_to_nfsv4_one() can then write past the end of its allocation.
Symptoms were slab corruption warnings.
Also, some minor cleanup while we're here. (Among other things, note
that the first few lines guarantee that pacl is non-NULL.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index d3a5871..d190e33 100644
--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -151,17 +151,15 @@
pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
if (IS_ERR(pacl))
return PTR_ERR(pacl);
- /* allocate for worst case: one (deny, allow) pair each: */
- size += 2 * pacl->a_count;
}
+ /* allocate for worst case: one (deny, allow) pair each: */
+ size += 2 * pacl->a_count;
if (S_ISDIR(inode->i_mode)) {
flags = NFS4_ACL_DIR;
dpacl = get_acl(inode, ACL_TYPE_DEFAULT);
if (dpacl)
size += 2 * dpacl->a_count;
- } else {
- dpacl = NULL;
}
*acl = nfs4_acl_new(size);
@@ -170,8 +168,7 @@
goto out;
}
- if (pacl)
- _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
+ _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
if (dpacl)
_posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);