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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-28 09:50:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-28 09:50:25 -0800
commit3bad8bb5cd3048a67df43ac6b1e2f191f19d9ff0 (patch)
treebc18e38958f63b6ffb8514e16729f094925e4d5b
parent5ecbe3c3c690b5ab493c730c317475287a9e8b45 (diff)
parentf19e84df37bda502a2248d507a9cf2b9e693279e (diff)
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
-rw-r--r--fs/cifs/cifsglob.h1
-rw-r--r--fs/cifs/ioctl.c6
-rw-r--r--fs/cifs/smb2ops.c99
-rw-r--r--fs/cifs/smb2pdu.c92
-rw-r--r--fs/cifs/smb2pdu.h12
-rw-r--r--fs/cifs/smb2proto.h1
-rw-r--r--fs/cifs/smbfsctl.h2
7 files changed, 189 insertions, 24 deletions
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index d9ea7ada1378..f918a998a087 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -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 {
diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
index 409b45eefe70..77492301cc2b 100644
--- a/fs/cifs/ioctl.c
+++ b/fs/cifs/ioctl.c
@@ -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:
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 11dde4b24f8a..757da3e54d3d 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -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 = {
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index d65270c290a1..2013234b73ad 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -454,6 +454,81 @@ neg_exit:
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;
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index f88320bbb477..2022c542ea3a 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -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
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index b4eea105b08c..93adc64666f3 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -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 */
diff --git a/fs/cifs/smbfsctl.h b/fs/cifs/smbfsctl.h
index a4b2391fe66e..0e538b5c9622 100644
--- a/fs/cifs/smbfsctl.h
+++ b/fs/cifs/smbfsctl.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