6.12-stable review patch. If anyone has any objections, please let me know.
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From: Pali Rohár pali@kernel.org
[ Upstream commit 56e84c64fc257a95728ee73165456b025c48d408 ]
Validate the SMB1 query reparse point response per [MS-CIFS] section 2.2.7.2 NT_TRANSACT_IOCTL.
NT_TRANSACT_IOCTL response contains one word long setup data after which is ByteCount member. So check that SetupCount is 1 before trying to read and use ByteCount member.
Output setup data contains ReturnedDataLen member which is the output length of executed IOCTL command by remote system. So check that output was not truncated before transferring over network.
Change MaxSetupCount of NT_TRANSACT_IOCTL request from 4 to 1 as io_rsp structure already expects one word long output setup data. This should prevent server sending incompatible structure (in case it would be extended in future, which is unlikely).
Change MaxParameterCount of NT_TRANSACT_IOCTL request from 2 to 0 as NT IOCTL does not have any documented output parameters and this function does not parse any output parameters at all.
Fixes: ed3e0a149b58 ("smb: client: implement ->query_reparse_point() for SMB1") Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifssmb.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 8667f403a0ab6..cf8d9de2298fc 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -2780,10 +2780,10 @@ int cifs_query_reparse_point(const unsigned int xid,
io_req->TotalParameterCount = 0; io_req->TotalDataCount = 0; - io_req->MaxParameterCount = cpu_to_le32(2); + io_req->MaxParameterCount = cpu_to_le32(0); /* BB find exact data count max from sess structure BB */ io_req->MaxDataCount = cpu_to_le32(CIFSMaxBufSize & 0xFFFFFF00); - io_req->MaxSetupCount = 4; + io_req->MaxSetupCount = 1; io_req->Reserved = 0; io_req->ParameterOffset = 0; io_req->DataCount = 0; @@ -2810,6 +2810,22 @@ int cifs_query_reparse_point(const unsigned int xid, goto error; }
+ /* SetupCount must be 1, otherwise offset to ByteCount is incorrect. */ + if (io_rsp->SetupCount != 1) { + rc = -EIO; + goto error; + } + + /* + * ReturnedDataLen is output length of executed IOCTL. + * DataCount is output length transferred over network. + * Check that we have full FSCTL_GET_REPARSE_POINT buffer. + */ + if (data_count != le16_to_cpu(io_rsp->ReturnedDataLen)) { + rc = -EIO; + goto error; + } + end = 2 + get_bcc(&io_rsp->hdr) + (__u8 *)&io_rsp->ByteCount; start = (__u8 *)&io_rsp->hdr.Protocol + data_offset; if (start >= end) {