6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joshua Rogers linux@joshua.hu
commit 4012abe8a78fbb8869634130024266eaef7081fe upstream.
SMB2_change_notify called smb2_validate_iov() but ignored the return code, then kmemdup()ed using server provided OutputBufferOffset/Length.
Check the return of smb2_validate_iov() and bail out on error.
Discovered with help from the ZeroPath security tooling.
Signed-off-by: Joshua Rogers linux@joshua.hu Reviewed-by: Paulo Alcantara (Red Hat) pc@manguebit.org Cc: stable@vger.kernel.org Fixes: e3e9463414f61 ("smb3: improve SMB3 change notification support") Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/smb2pdu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -3837,9 +3837,12 @@ SMB2_change_notify(const unsigned int xi
smb_rsp = (struct smb2_change_notify_rsp *)rsp_iov.iov_base;
- smb2_validate_iov(le16_to_cpu(smb_rsp->OutputBufferOffset), - le32_to_cpu(smb_rsp->OutputBufferLength), &rsp_iov, + rc = smb2_validate_iov(le16_to_cpu(smb_rsp->OutputBufferOffset), + le32_to_cpu(smb_rsp->OutputBufferLength), + &rsp_iov, sizeof(struct file_notify_information)); + if (rc) + goto cnotify_exit;
*out_data = kmemdup((char *)smb_rsp + le16_to_cpu(smb_rsp->OutputBufferOffset), le32_to_cpu(smb_rsp->OutputBufferLength), GFP_KERNEL);