[PATCH 5.19 082/155] cifs: fix small mempool leak in SMB2_negotiate()

Greg Kroah-Hartman
2022-09-06T14:11:27Z

From: Enzo Matsumiya <ematsumiya@suse.de>

commit 27893dfc1285f80f80f46b3b8c95f5d15d2e66d0 upstream.

In some cases of failure (dialect mismatches) in SMB2_negotiate(), after
the request is sent, the checks would return -EIO when they should be
rather setting rc = -EIO and jumping to neg_exit to free the response
buffer from mempool.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Cc: stable@vger.kernel.org
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/cifs/smb2pdu.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -964,16 +964,17 @@ SMB2_negotiate(const unsigned int xid,
} else if (rc != 0)
goto neg_exit;

+ rc = -EIO;
if (strcmp(server->vals->version_string,
SMB3ANY_VERSION_STRING) == 0) {
if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
cifs_server_dbg(VFS,
"SMB2 dialect returned but not requested\n");
- return -EIO;
+ goto neg_exit;
} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
cifs_server_dbg(VFS,
"SMB2.1 dialect returned but not requested\n");
- return -EIO;
+ goto neg_exit;
} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
/* ops set to 3.0 by default for default so update */
server->ops = &smb311_operations;
@@ -984,7 +985,7 @@ SMB2_negotiate(const unsigned int xid,
if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
cifs_server_dbg(VFS,
"SMB2 dialect returned but not requested\n");
- return -EIO;
+ goto neg_exit;
} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
/* ops set to 3.0 by default for default so update */
server->ops = &smb21_operations;
@@ -998,7 +999,7 @@ SMB2_negotiate(const unsigned int xid,
/* if requested single dialect ensure returned dialect matched */
cifs_server_dbg(VFS, "Invalid 0x%x dialect returned: not requested\n",
le16_to_cpu(rsp->DialectRevision));
- return -EIO;
+ goto neg_exit;
}

cifs_dbg(FYI, "mode 0x%x\n", rsp->SecurityMode);
@@ -1016,9 +1017,10 @@ SMB2_negotiate(const unsigned int xid,
else {
cifs_server_dbg(VFS, "Invalid dialect returned by server 0x%x\n",
le16_to_cpu(rsp->DialectRevision));
- rc = -EIO;
goto neg_exit;
}
+
+ rc = 0;
server->dialect = le16_to_cpu(rsp->DialectRevision);

/*