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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-28 18:50:25 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-28 18:50:25 +0100 |
commit | 3bad8bb5cd3048a67df43ac6b1e2f191f19d9ff0 (patch) | |
tree | bc18e38958f63b6ffb8514e16729f094925e4d5b /fs | |
parent | kernel/extable: fix address-checks for core_kernel and init areas (diff) | |
parent | [CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload (diff) | |
download | linux-3bad8bb5cd3048a67df43ac6b1e2f191f19d9ff0.tar.xz linux-3bad8bb5cd3048a67df43ac6b1e2f191f19d9ff0.zip |
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
Diffstat (limited to 'fs')
-rw-r--r-- | fs/cifs/cifsglob.h | 1 | ||||
-rw-r--r-- | fs/cifs/ioctl.c | 6 | ||||
-rw-r--r-- | fs/cifs/smb2ops.c | 99 | ||||
-rw-r--r-- | fs/cifs/smb2pdu.c | 92 | ||||
-rw-r--r-- | fs/cifs/smb2pdu.h | 12 | ||||
-rw-r--r-- | fs/cifs/smb2proto.h | 1 | ||||
-rw-r--r-- | fs/cifs/smbfsctl.h | 2 |
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 |