From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 097f5863b1a0c9901f180bbd56ae7d630655faaa ]
We need to verify that the "data_offset" is within bounds.
Reported-by: Dr Silvio Cesare of InfoSect silvio.cesare@gmail.com Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Steve French stfrench@microsoft.com Reviewed-by: Aurelien Aptel aaptel@suse.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- fs/cifs/misc.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index eedbc34e19db..c8662e212afc 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -405,9 +405,17 @@ is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) (struct smb_com_transaction_change_notify_rsp *)buf; struct file_notify_information *pnotify; __u32 data_offset = 0; + size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length); + if (get_bcc(buf) > sizeof(struct file_notify_information)) { data_offset = le32_to_cpu(pSMBr->DataOffset);
+ if (data_offset > + len - sizeof(struct file_notify_information)) { + cifs_dbg(FYI, "invalid data_offset %u\n", + data_offset); + return true; + } pnotify = (struct file_notify_information *) ((char *)&pSMBr->hdr.Protocol + data_offset); cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",