4.20-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit 73aaf920cc72024c4a4460cfa46d56e5014172f3 ]
The call to SMB2_queary_acl can allocate memory to pntsd and also return a failure via a call to SMB2_query_acl (and then query_info). This occurs when query_info allocates the structure and then in query_info the call to smb2_validate_and_copy_iov fails. Currently the failure just returns without kfree'ing pntsd hence causing a memory leak.
Currently, *data is allocated if it's not already pointing to a buffer, so it needs to be kfree'd only if was allocated in query_info, so the fix adds an allocated flag to track this. Also set *dlen to zero on an error just to be safe since *data is kfree'd.
Also set errno to -ENOMEM if the allocation of *data fails.
Signed-off-by: Colin Ian King colin.king@canonical.com Signed-off-by: Steve French stfrench@microsoft.com Reviewed-by: Dan Carpener dan.carpenter@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/smb2pdu.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 28712080add97..3c44c51310c4b 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2714,6 +2714,7 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, int resp_buftype = CIFS_NO_BUFFER; struct cifs_ses *ses = tcon->ses; int flags = 0; + bool allocated = false;
cifs_dbg(FYI, "Query Info\n");
@@ -2753,14 +2754,21 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, "Error %d allocating memory for acl\n", rc); *dlen = 0; + rc = -ENOMEM; goto qinf_exit; } + allocated = true; } }
rc = smb2_validate_and_copy_iov(le16_to_cpu(rsp->OutputBufferOffset), le32_to_cpu(rsp->OutputBufferLength), &rsp_iov, min_len, *data); + if (rc && allocated) { + kfree(*data); + *data = NULL; + *dlen = 0; + }
qinf_exit: SMB2_query_info_free(&rqst);