From 0544b324e62c177c3a9e9c3bdce22e6db9f34588 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Thu, 20 Dec 2018 23:50:48 -0600 Subject: [PATCH] cifs: check kzalloc return kzalloc can return NULL so an additional check is needed. While there is a check for ret_buf there is no check for the allocation of ret_buf->crfid.fid - this check is thus added. Both call-sites of tconInfoAlloc() check for NULL return of tconInfoAlloc() so returning NULL on failure of kzalloc() here seems appropriate. As the kzalloc() is the only thing here that can fail it is moved to the beginning so as not to initialize other resources on failure of kzalloc. Fixes: 3d4ef9a15343 ("smb3: fix redundant opens on root") Signed-off-by: Joe Perches Signed-off-by: Steve French --- fs/cifs/misc.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 5e315e4009e2..10ae1a35b6f7 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -111,21 +111,27 @@ struct cifs_tcon * tconInfoAlloc(void) { struct cifs_tcon *ret_buf; - ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL); - if (ret_buf) { - atomic_inc(&tconInfoAllocCount); - ret_buf->tidStatus = CifsNew; - ++ret_buf->tc_count; - INIT_LIST_HEAD(&ret_buf->openFileList); - INIT_LIST_HEAD(&ret_buf->tcon_list); - spin_lock_init(&ret_buf->open_file_lock); - mutex_init(&ret_buf->crfid.fid_mutex); - ret_buf->crfid.fid = kzalloc(sizeof(struct cifs_fid), - GFP_KERNEL); - spin_lock_init(&ret_buf->stat_lock); - atomic_set(&ret_buf->num_local_opens, 0); - atomic_set(&ret_buf->num_remote_opens, 0); + + ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL); + if (!ret_buf) + return NULL; + ret_buf->crfid.fid = kzalloc(sizeof(*ret_buf->crfid.fid), GFP_KERNEL); + if (!ret_buf->crfid.fid) { + kfree(ret_buf); + return NULL; } + + atomic_inc(&tconInfoAllocCount); + ret_buf->tidStatus = CifsNew; + ++ret_buf->tc_count; + INIT_LIST_HEAD(&ret_buf->openFileList); + INIT_LIST_HEAD(&ret_buf->tcon_list); + spin_lock_init(&ret_buf->open_file_lock); + mutex_init(&ret_buf->crfid.fid_mutex); + spin_lock_init(&ret_buf->stat_lock); + atomic_set(&ret_buf->num_local_opens, 0); + atomic_set(&ret_buf->num_remote_opens, 0); + return ret_buf; }