Commit 3bad8bb5 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "SMB3 "validate negotiate" is needed to prevent certain types of
  downgrade attacks.

  Also changes SMB2/SMB3 copy offload from using the BTRFS copy ioctl
  (BTRFS_IOC_CLONE) to a cifs specific ioctl (CIFS_IOC_COPYCHUNK_FILE)
  to address Christoph's comment that there are semantic differences
  between requesting copy offload in which copy-on-write is mandatory
  (as in the BTRFS ioctl) and optional in the SMB2/SMB3 case.  Also
  fixes SMB2/SMB3 copychunk for large files"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  [CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload
  Check SMB3 dialects against downgrade attacks
  Removed duplicated (and unneeded) goto
  CIFS: Fix SMB2/SMB3 Copy offload support (refcopy) for large files
parents 5ecbe3c3 f19e84df
......@@ -384,6 +384,7 @@ struct smb_version_operations {
int (*clone_range)(const unsigned int, struct cifsFileInfo *src_file,
struct cifsFileInfo *target_file, u64 src_off, u64 len,
u64 dest_off);
int (*validate_negotiate)(const unsigned int, struct cifs_tcon *);
};
struct smb_version_values {
......
......@@ -26,13 +26,15 @@
#include <linux/mount.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/btrfs.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifsfs.h"
#define CIFS_IOCTL_MAGIC 0xCF
#define CIFS_IOC_COPYCHUNK_FILE _IOW(CIFS_IOCTL_MAGIC, 3, int)
static long cifs_ioctl_clone(unsigned int xid, struct file *dst_file,
unsigned long srcfd, u64 off, u64 len, u64 destoff)
{
......@@ -213,7 +215,7 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
cifs_dbg(FYI, "set compress flag rc %d\n", rc);
}
break;
case BTRFS_IOC_CLONE:
case CIFS_IOC_COPYCHUNK_FILE:
rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0);
break;
default:
......
......@@ -532,7 +532,10 @@ smb2_clone_range(const unsigned int xid,
int rc;
unsigned int ret_data_len;
struct copychunk_ioctl *pcchunk;
char *retbuf = NULL;
struct copychunk_ioctl_rsp *retbuf = NULL;
struct cifs_tcon *tcon;
int chunks_copied = 0;
bool chunk_sizes_updated = false;
pcchunk = kmalloc(sizeof(struct copychunk_ioctl), GFP_KERNEL);
......@@ -547,27 +550,96 @@ smb2_clone_range(const unsigned int xid,
/* Note: request_res_key sets res_key null only if rc !=0 */
if (rc)
return rc;
goto cchunk_out;
/* For now array only one chunk long, will make more flexible later */
pcchunk->ChunkCount = __constant_cpu_to_le32(1);
pcchunk->Reserved = 0;
pcchunk->SourceOffset = cpu_to_le64(src_off);
pcchunk->TargetOffset = cpu_to_le64(dest_off);
pcchunk->Length = cpu_to_le32(len);
pcchunk->Reserved2 = 0;
/* Request that server copy to target from src file identified by key */
rc = SMB2_ioctl(xid, tlink_tcon(trgtfile->tlink),
trgtfile->fid.persistent_fid,
trgtfile->fid.volatile_fid, FSCTL_SRV_COPYCHUNK_WRITE,
true /* is_fsctl */, (char *)pcchunk,
sizeof(struct copychunk_ioctl), &retbuf, &ret_data_len);
tcon = tlink_tcon(trgtfile->tlink);
/* BB need to special case rc = EINVAL to alter chunk size */
while (len > 0) {
pcchunk->SourceOffset = cpu_to_le64(src_off);
pcchunk->TargetOffset = cpu_to_le64(dest_off);
pcchunk->Length =
cpu_to_le32(min_t(u32, len, tcon->max_bytes_chunk));
cifs_dbg(FYI, "rc %d data length out %d\n", rc, ret_data_len);
/* Request server copy to target from src identified by key */
rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,
trgtfile->fid.volatile_fid, FSCTL_SRV_COPYCHUNK_WRITE,
true /* is_fsctl */, (char *)pcchunk,
sizeof(struct copychunk_ioctl), (char **)&retbuf,
&ret_data_len);
if (rc == 0) {
if (ret_data_len !=
sizeof(struct copychunk_ioctl_rsp)) {
cifs_dbg(VFS, "invalid cchunk response size\n");
rc = -EIO;
goto cchunk_out;
}
if (retbuf->TotalBytesWritten == 0) {
cifs_dbg(FYI, "no bytes copied\n");
rc = -EIO;
goto cchunk_out;
}
/*
* Check if server claimed to write more than we asked
*/
if (le32_to_cpu(retbuf->TotalBytesWritten) >
le32_to_cpu(pcchunk->Length)) {
cifs_dbg(VFS, "invalid copy chunk response\n");
rc = -EIO;
goto cchunk_out;
}
if (le32_to_cpu(retbuf->ChunksWritten) != 1) {
cifs_dbg(VFS, "invalid num chunks written\n");
rc = -EIO;
goto cchunk_out;
}
chunks_copied++;
src_off += le32_to_cpu(retbuf->TotalBytesWritten);
dest_off += le32_to_cpu(retbuf->TotalBytesWritten);
len -= le32_to_cpu(retbuf->TotalBytesWritten);
cifs_dbg(FYI, "Chunks %d PartialChunk %d Total %d\n",
le32_to_cpu(retbuf->ChunksWritten),
le32_to_cpu(retbuf->ChunkBytesWritten),
le32_to_cpu(retbuf->TotalBytesWritten));
} else if (rc == -EINVAL) {
if (ret_data_len != sizeof(struct copychunk_ioctl_rsp))
goto cchunk_out;
cifs_dbg(FYI, "MaxChunks %d BytesChunk %d MaxCopy %d\n",
le32_to_cpu(retbuf->ChunksWritten),
le32_to_cpu(retbuf->ChunkBytesWritten),
le32_to_cpu(retbuf->TotalBytesWritten));
/*
* Check if this is the first request using these sizes,
* (ie check if copy succeed once with original sizes
* and check if the server gave us different sizes after
* we already updated max sizes on previous request).
* if not then why is the server returning an error now
*/
if ((chunks_copied != 0) || chunk_sizes_updated)
goto cchunk_out;
/* Check that server is not asking us to grow size */
if (le32_to_cpu(retbuf->ChunkBytesWritten) <
tcon->max_bytes_chunk)
tcon->max_bytes_chunk =
le32_to_cpu(retbuf->ChunkBytesWritten);
else
goto cchunk_out; /* server gave us bogus size */
/* No need to change MaxChunks since already set to 1 */
chunk_sizes_updated = true;
}
}
cchunk_out:
kfree(pcchunk);
return rc;
}
......@@ -1247,6 +1319,7 @@ struct smb_version_operations smb30_operations = {
.create_lease_buf = smb3_create_lease_buf,
.parse_lease_buf = smb3_parse_lease_buf,
.clone_range = smb2_clone_range,
.validate_negotiate = smb3_validate_negotiate,
};
struct smb_version_values smb20_values = {
......
......@@ -454,6 +454,81 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
return rc;
}
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_rsp *pneg_rsp;
u32 rsplen;
cifs_dbg(FYI, "validate negotiate\n");
/*
* validation ioctl must be signed, so no point sending this if we
* can not sign it. We could eventually change this to selectively
* sign just this, the first and only signed request on a connection.
* This is good enough for now since a user who wants better security
* would also enable signing on the mount. Having validation of
* negotiate info for signed connections helps reduce attack vectors
*/
if (tcon->ses->server->sign == false)
return 0; /* validation requires signing */
vneg_inbuf.Capabilities =
cpu_to_le32(tcon->ses->server->vals->req_capabilities);
memcpy(vneg_inbuf.Guid, cifs_client_guid, SMB2_CLIENT_GUID_SIZE);
if (tcon->ses->sign)
vneg_inbuf.SecurityMode =
cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
else if (global_secflags & CIFSSEC_MAY_SIGN)
vneg_inbuf.SecurityMode =
cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
else
vneg_inbuf.SecurityMode = 0;
vneg_inbuf.DialectCount = cpu_to_le16(1);
vneg_inbuf.Dialects[0] =
cpu_to_le16(tcon->ses->server->vals->protocol_id);
rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
(char *)&vneg_inbuf, sizeof(struct validate_negotiate_info_req),
(char **)&pneg_rsp, &rsplen);
if (rc != 0) {
cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
return -EIO;
}
if (rsplen != sizeof(struct validate_negotiate_info_rsp)) {
cifs_dbg(VFS, "invalid size of protocol negotiate response\n");
return -EIO;
}
/* check validate negotiate info response matches what we got earlier */
if (pneg_rsp->Dialect !=
cpu_to_le16(tcon->ses->server->vals->protocol_id))
goto vneg_out;
if (pneg_rsp->SecurityMode != cpu_to_le16(tcon->ses->server->sec_mode))
goto vneg_out;
/* do not validate server guid because not saved at negprot time yet */
if ((le32_to_cpu(pneg_rsp->Capabilities) | SMB2_NT_FIND |
SMB2_LARGE_FILES) != tcon->ses->server->capabilities)
goto vneg_out;
/* validate negotiate successful */
cifs_dbg(FYI, "validate negotiate info successful\n");
return 0;
vneg_out:
cifs_dbg(VFS, "protocol revalidation - security settings mismatch\n");
return -EIO;
}
int
SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
const struct nls_table *nls_cp)
......@@ -829,6 +904,8 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
((tcon->share_flags & SHI1005_FLAGS_DFS) == 0))
cifs_dbg(VFS, "DFS capability contradicts DFS flag\n");
init_copy_chunk_defaults(tcon);
if (tcon->ses->server->ops->validate_negotiate)
rc = tcon->ses->server->ops->validate_negotiate(xid, tcon);
tcon_exit:
free_rsp_buf(resp_buftype, rsp);
kfree(unc_path);
......@@ -1214,10 +1291,17 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
rc = SendReceive2(xid, ses, iov, num_iovecs, &resp_buftype, 0);
rsp = (struct smb2_ioctl_rsp *)iov[0].iov_base;
if (rc != 0) {
if ((rc != 0) && (rc != -EINVAL)) {
if (tcon)
cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
goto ioctl_exit;
} else if (rc == -EINVAL) {
if ((opcode != FSCTL_SRV_COPYCHUNK_WRITE) &&
(opcode != FSCTL_SRV_COPYCHUNK)) {
if (tcon)
cifs_stats_fail_inc(tcon, SMB2_IOCTL_HE);
goto ioctl_exit;
}
}
/* check if caller wants to look at return data or just return rc */
......@@ -2154,11 +2238,9 @@ send_set_info(const unsigned int xid, struct cifs_tcon *tcon,
rc = SendReceive2(xid, ses, iov, num, &resp_buftype, 0);
rsp = (struct smb2_set_info_rsp *)iov[0].iov_base;
if (rc != 0) {
if (rc != 0)
cifs_stats_fail_inc(tcon, SMB2_SET_INFO_HE);
goto out;
}
out:
free_rsp_buf(resp_buftype, rsp);
kfree(iov);
return rc;
......
......@@ -577,13 +577,19 @@ struct copychunk_ioctl_rsp {
__le32 TotalBytesWritten;
} __packed;
/* Response and Request are the same format */
struct validate_negotiate_info {
struct validate_negotiate_info_req {
__le32 Capabilities;
__u8 Guid[SMB2_CLIENT_GUID_SIZE];
__le16 SecurityMode;
__le16 DialectCount;
__le16 Dialect[1];
__le16 Dialects[1]; /* dialect (someday maybe list) client asked for */
} __packed;
struct validate_negotiate_info_rsp {
__le32 Capabilities;
__u8 Guid[SMB2_CLIENT_GUID_SIZE];
__le16 SecurityMode;
__le16 Dialect; /* Dialect in use for the connection */
} __packed;
#define RSS_CAPABLE 0x00000001
......
......@@ -162,5 +162,6 @@ extern int smb2_lockv(const unsigned int xid, struct cifs_tcon *tcon,
struct smb2_lock_element *buf);
extern int SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon,
__u8 *lease_key, const __le32 lease_state);
extern int smb3_validate_negotiate(const unsigned int, struct cifs_tcon *);
#endif /* _SMB2PROTO_H */
......@@ -90,7 +90,7 @@
#define FSCTL_LMR_REQUEST_RESILIENCY 0x001401D4 /* BB add struct */
#define FSCTL_LMR_GET_LINK_TRACK_INF 0x001400E8 /* BB add struct */
#define FSCTL_LMR_SET_LINK_TRACK_INF 0x001400EC /* BB add struct */
#define FSCTL_VALIDATE_NEGOTIATE_INFO 0x00140204 /* BB add struct */
#define FSCTL_VALIDATE_NEGOTIATE_INFO 0x00140204
/* Perform server-side data movement */
#define FSCTL_SRV_COPYCHUNK 0x001440F2
#define FSCTL_SRV_COPYCHUNK_WRITE 0x001480F2
......
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