-----Original Message----- From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma- owner@vger.kernel.org] On Behalf Of Long Li Sent: Monday, April 16, 2018 7:49 PM To: Steve French sfrench@samba.org; linux-cifs@vger.kernel.org; samba- technical@lists.samba.org; linux-kernel@vger.kernel.org; linux- rdma@vger.kernel.org; stable@vger.kernel.org Cc: longli longli@microsoft.com Subject: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc
From: Long Li longli@microsoft.com
The data buffer allocated on the stack can't be DMA'ed, and hence can't send through RDMA via SMB Direct.
Fix this by allocating the request on the heap in smb3_validate_negotiate.
Please provide Fixes ("12-letters commit id") "commit string" which introduced this issue and it is getting fixed here, so that other can apply this fix to older versions.
Signed-off-by: Long Li longli@microsoft.com
fs/cifs/smb2pdu.c | 38 ++++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 0f044c4..abbefe2 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses) int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon) { int rc = 0;
- struct validate_negotiate_info_req vneg_inbuf;
- struct validate_negotiate_info_req *pneg_inbuf;
[..]
rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
(char *)&vneg_inbuf, sizeof(structvalidate_negotiate_info_req),
(char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),(char **)&pneg_rsp, &rsplen);
if (rc != 0) { cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
kfree(pneg_inbuf);return -EIO;
Instead of duplicating code here, please jump to err_rsp_free label. Kfree() takes care to not panic for NULL pointer. Or for clarity define new label.
}
@@ -838,12 +842,14 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
/* validate negotiate successful */ cifs_dbg(FYI, "validate negotiate info successful\n");
- kfree(pneg_inbuf); kfree(pneg_rsp); return 0;
vneg_out: cifs_dbg(VFS, "protocol revalidation - security settings mismatch\n"); err_rsp_free:
- kfree(pneg_inbuf); kfree(pneg_rsp); return -EIO;
}
2.7.4
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