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

Pull CIFS fixes from Steve French:
 "Three cifs fixes, the most important fixing the problem with passing
  bogus pointers with writev (CVE-2014-0069).

  Two additional cifs fixes are still in review (including the fix for
  an append problem which Al also discovered)"

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix too big maxBuf size for SMB3 mounts
  cifs: ensure that uncached writes handle unmapped areas correctly
  [CIFS] Fix cifsacl mounts over smb2 to not call cifs

10 files changed, 78 insertions, 28 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index c819b0bd491a..7ff866dbb89e 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -865,8 +865,8 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
         return rc;
 }
 
-static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
-                __u16 fid, u32 *pacllen)
+struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
+                const struct cifs_fid *cifsfid, u32 *pacllen)
 {
         struct cifs_ntsd *pntsd = NULL;
         unsigned int xid;
@@ -877,7 +877,8 @@ static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
                 return ERR_CAST(tlink);
 
         xid = get_xid();
-        rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
+        rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), cifsfid->netfid, &pntsd,
+                                pacllen);
         free_xid(xid);
 
         cifs_put_tlink(tlink);
@@ -946,7 +947,7 @@ struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
         if (!open_file)
                 return get_cifs_acl_by_path(cifs_sb, path, pacllen);
 
-        pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->fid.netfid, pacllen);
+        pntsd = get_cifs_acl_by_fid(cifs_sb, &open_file->fid, pacllen);
         cifsFileInfo_put(open_file);
         return pntsd;
 }
@@ -1006,19 +1007,31 @@ out:
 /* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
 int
 cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
-                  struct inode *inode, const char *path, const __u16 *pfid)
+                  struct inode *inode, const char *path,
+                  const struct cifs_fid *pfid)
 {
         struct cifs_ntsd *pntsd = NULL;
         u32 acllen = 0;
         int rc = 0;
+        struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+        struct cifs_tcon *tcon;
 
         cifs_dbg(NOISY, "converting ACL to mode for %s\n", path);
 
-        if (pfid)
-                pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen);
-        else
-                pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
+        if (IS_ERR(tlink))
+                return PTR_ERR(tlink);
+        tcon = tlink_tcon(tlink);
 
+        if (pfid && (tcon->ses->server->ops->get_acl_by_fid))
+                pntsd = tcon->ses->server->ops->get_acl_by_fid(cifs_sb, pfid,
+                                                          &acllen);
+        else if (tcon->ses->server->ops->get_acl)
+                pntsd = tcon->ses->server->ops->get_acl(cifs_sb, inode, path,
+                                                        &acllen);
+        else {
+                cifs_put_tlink(tlink);
+                return -EOPNOTSUPP;
+        }
         /* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
         if (IS_ERR(pntsd)) {
                 rc = PTR_ERR(pntsd);
@@ -1030,6 +1043,8 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
                         cifs_dbg(VFS, "parse sec desc failed rc = %d\n", rc);
         }
 
+        cifs_put_tlink(tlink);
+
         return rc;
 }
 
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 86dc28c7aa5c..cf32f0393369 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -398,6 +398,8 @@ struct smb_version_operations {
                         const struct nls_table *, int);
         struct cifs_ntsd * (*get_acl)(struct cifs_sb_info *, struct inode *,
                         const char *, u32 *);
+        struct cifs_ntsd * (*get_acl_by_fid)(struct cifs_sb_info *,
+                        const struct cifs_fid *, u32 *);
         int (*set_acl)(struct cifs_ntsd *, __u32, struct inode *, const char *,
                         int);
 };
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index d00e09dfc452..acc4ee8ed075 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -151,7 +151,7 @@ extern struct inode *cifs_iget(struct super_block *sb,
 
 extern int cifs_get_inode_info(struct inode **inode, const char *full_path,
                                FILE_ALL_INFO *data, struct super_block *sb,
-                               int xid, const __u16 *fid);
+                               int xid, const struct cifs_fid *fid);
 extern int cifs_get_inode_info_unix(struct inode **pinode,
                         const unsigned char *search_path,
                         struct super_block *sb, unsigned int xid);
@@ -162,11 +162,13 @@ extern int cifs_rename_pending_delete(const char *full_path,
                                       const unsigned int xid);
 extern int cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
                               struct cifs_fattr *fattr, struct inode *inode,
-                              const char *path, const __u16 *pfid);
+                              const char *path, const struct cifs_fid *pfid);
 extern int id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64,
                                         kuid_t, kgid_t);
 extern struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *, struct inode *,
                                         const char *, u32 *);
+extern struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *,
+                                                const struct cifs_fid *, u32 *);
 extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
                                 const char *, int);
 
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index d3a6796caa5a..3db0c5fd9a11 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -378,7 +378,7 @@ cifs_create_get_file_info:
                                               xid);
         else {
                 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
-                                         xid, &fid->netfid);
+                                         xid, fid);
                 if (newinode) {
                         if (server->ops->set_lease_key)
                                 server->ops->set_lease_key(newinode, fid);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 755584684f6c..53c15074bb36 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -244,7 +244,7 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
                                               xid);
         else
                 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
-                                         xid, &fid->netfid);
+                                         xid, fid);
 
 out:
         kfree(buf);
@@ -2389,7 +2389,7 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
                  unsigned long nr_segs, loff_t *poffset)
 {
         unsigned long nr_pages, i;
-        size_t copied, len, cur_len;
+        size_t bytes, copied, len, cur_len;
         ssize_t total_written = 0;
         loff_t offset;
         struct iov_iter it;
@@ -2444,14 +2444,45 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
 
                 save_len = cur_len;
                 for (i = 0; i < nr_pages; i++) {
-                        copied = min_t(const size_t, cur_len, PAGE_SIZE);
+                        bytes = min_t(const size_t, cur_len, PAGE_SIZE);
                         copied = iov_iter_copy_from_user(wdata->pages[i], &it,
-                                                         0, copied);
+                                                         0, bytes);
                         cur_len -= copied;
                         iov_iter_advance(&it, copied);
+                        /*
+                         * If we didn't copy as much as we expected, then that
+                         * may mean we trod into an unmapped area. Stop copying
+                         * at that point. On the next pass through the big
+                         * loop, we'll likely end up getting a zero-length
+                         * write and bailing out of it.
+                         */
+                        if (copied < bytes)
+                                break;
                 }
                 cur_len = save_len - cur_len;
 
+                /*
+                 * If we have no data to send, then that probably means that
+                 * the copy above failed altogether. That's most likely because
+                 * the address in the iovec was bogus. Set the rc to -EFAULT,
+                 * free anything we allocated and bail out.
+                 */
+                if (!cur_len) {
+                        for (i = 0; i < nr_pages; i++)
+                                put_page(wdata->pages[i]);
+                        kfree(wdata);
+                        rc = -EFAULT;
+                        break;
+                }
+
+                /*
+                 * i + 1 now represents the number of pages we actually used in
+                 * the copy phase above. Bring nr_pages down to that, and free
+                 * any pages that we didn't use.
+                 */
+                for ( ; nr_pages > i + 1; nr_pages--)
+                        put_page(wdata->pages[nr_pages - 1]);
+
                 wdata->sync_mode = WB_SYNC_ALL;
                 wdata->nr_pages = nr_pages;
                 wdata->offset = (__u64)offset;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index be58b8fcdb3c..aadc2b68678b 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -677,7 +677,7 @@ cgfi_exit:
 int
 cifs_get_inode_info(struct inode **inode, const char *full_path,
                     FILE_ALL_INFO *data, struct super_block *sb, int xid,
-                    const __u16 *fid)
+                    const struct cifs_fid *fid)
 {
         bool validinum = false;
         __u16 srchflgs;
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index bfd66d84831e..526fb89f9230 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -1073,6 +1073,7 @@ struct smb_version_operations smb1_operations = {
 #endif /* CIFS_XATTR */
 #ifdef CONFIG_CIFS_ACL
         .get_acl = get_cifs_acl,
+        .get_acl_by_fid = get_cifs_acl_by_fid,
         .set_acl = set_cifs_acl,
 #endif /* CIFS_ACL */
 };
diff --git a/fs/cifs/smb2glob.h b/fs/cifs/smb2glob.h
index c38350851b08..bc0bb9c34f72 100644
--- a/fs/cifs/smb2glob.h
+++ b/fs/cifs/smb2glob.h
@@ -57,4 +57,7 @@
 #define SMB2_CMACAES_SIZE (16)
 #define SMB3_SIGNKEY_SIZE (16)
 
+/* Maximum buffer size value we can send with 1 credit */
+#define SMB2_MAX_BUFFER_SIZE 65536
+
 #endif  /* _SMB2_GLOB_H */
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 757da3e54d3d..192f51a12cf1 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -182,11 +182,8 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
         /* start with specified wsize, or default */
         wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE;
         wsize = min_t(unsigned int, wsize, server->max_write);
-        /*
-         * limit write size to 2 ** 16, because we don't support multicredit
-         * requests now.
-         */
-        wsize = min_t(unsigned int, wsize, 2 << 15);
+        /* set it to the maximum buffer size value we can send with 1 credit */
+        wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);
 
         return wsize;
 }
@@ -200,11 +197,8 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
         /* start with specified rsize, or default */
         rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE;
         rsize = min_t(unsigned int, rsize, server->max_read);
-        /*
-         * limit write size to 2 ** 16, because we don't support multicredit
-         * requests now.
-         */
-        rsize = min_t(unsigned int, rsize, 2 << 15);
+        /* set it to the maximum buffer size value we can send with 1 credit */
+        rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE);
 
         return rsize;
 }
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a3f7a9c3cc69..860344701067 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -413,7 +413,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 
         /* SMB2 only has an extended negflavor */
         server->negflavor = CIFS_NEGFLAVOR_EXTENDED;
-        server->maxBuf = le32_to_cpu(rsp->MaxTransactSize);
+        /* set it to the maximum buffer size value we can send with 1 credit */
+        server->maxBuf = min_t(unsigned int, le32_to_cpu(rsp->MaxTransactSize),
+                               SMB2_MAX_BUFFER_SIZE);
         server->max_read = le32_to_cpu(rsp->MaxReadSize);
         server->max_write = le32_to_cpu(rsp->MaxWriteSize);
         /* BB Do we need to validate the SecurityMode? */