tentatively merged into cifs-2.6.git for-next pending more testing On Fri, Jan 14, 2022 at 5:04 PM Eugene Korenevsky <ekorenevsky@xxxxxxxxxxxxx> wrote: > > Windows SMB server responds with STATUS_OBJECT_NAME_INVALID code to > SMB2 QUERY_INFO request for "\<server>\<dfsname>\<linkpath>" DFS reference, > where <dfsname> contains non-ASCII unicode symbols. > > Check such DFS reference and emulate -EREMOTE if it is actual. > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215440 > Signed-off-by: Eugene Korenevsky <ekorenevsky@xxxxxxxxxxxxx> > --- > v2: No changes, this is a new patch in the patchset for #215440 fix > > fs/cifs/cifsproto.h | 5 +++++ > fs/cifs/connect.c | 5 +++++ > fs/cifs/inode.c | 6 ++++++ > fs/cifs/misc.c | 49 +++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 65 insertions(+) > > diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h > index 4f5a3e857df4..b3a9cc0def2c 100644 > --- a/fs/cifs/cifsproto.h > +++ b/fs/cifs/cifsproto.h > @@ -626,6 +626,11 @@ static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses, > int match_target_ip(struct TCP_Server_Info *server, > const char *share, size_t share_len, > bool *result); > + > +int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid, > + struct cifs_tcon *tcon, > + struct cifs_sb_info *cifs_sb, > + const char *dfs_link_path); > #endif > > static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options) > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > index 1060164b984a..db0f8a1c8fb5 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -3322,6 +3322,11 @@ static int is_path_remote(struct mount_ctx *mnt_ctx) > > rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, > full_path); > +#ifdef CONFIG_CIFS_DFS_UPCALL > + if (rc == -ENOENT && is_tcon_dfs(tcon)) > + rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb, > + full_path); > +#endif > if (rc != 0 && rc != -EREMOTE) { > kfree(full_path); > return rc; > diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c > index 279622e4eb1c..baa197edd8c5 100644 > --- a/fs/cifs/inode.c > +++ b/fs/cifs/inode.c > @@ -952,6 +952,12 @@ cifs_get_inode_info(struct inode **inode, > rc = server->ops->query_path_info(xid, tcon, cifs_sb, > full_path, tmp_data, > &adjust_tz, &is_reparse_point); > +#ifdef CONFIG_CIFS_DFS_UPCALL > + if (rc == -ENOENT && is_tcon_dfs(tcon)) > + rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, > + cifs_sb, > + full_path); > +#endif > data = tmp_data; > } > > diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c > index 5148d48d6a35..56598f7dbe00 100644 > --- a/fs/cifs/misc.c > +++ b/fs/cifs/misc.c > @@ -1302,4 +1302,53 @@ int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) > cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; > return 0; > } > + > +/** cifs_dfs_query_info_nonascii_quirk > + * Handle weird Windows SMB server behaviour. It responds with > + * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request > + * for "\<server>\<dfsname>\<linkpath>" DFS reference, > + * where <dfsname> contains non-ASCII unicode symbols. > + * > + * Check such DFS reference and emulate -ENOENT if it is actual. > + */ > +int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid, > + struct cifs_tcon *tcon, > + struct cifs_sb_info *cifs_sb, > + const char *linkpath) > +{ > + char *treename, *dfspath, sep; > + int treenamelen, linkpathlen, rc; > + > + treename = tcon->treeName; > + /* MS-DFSC: All paths in REQ_GET_DFS_REFERRAL and RESP_GET_DFS_REFERRAL > + * messages MUST be encoded with exactly one leading backslash, not two > + * leading backslashes. > + */ > + sep = CIFS_DIR_SEP(cifs_sb); > + if (treename[0] == sep && treename[1] == sep) > + treename++; > + linkpathlen = strlen(linkpath); > + treenamelen = strnlen(treename, MAX_TREE_SIZE + 1); > + dfspath = kzalloc(treenamelen + linkpathlen + 1, GFP_KERNEL); > + if (!dfspath) > + return -ENOMEM; > + if (treenamelen) > + memcpy(dfspath, treename, treenamelen); > + memcpy(dfspath + treenamelen, linkpath, linkpathlen); > + rc = dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, > + cifs_remap(cifs_sb), dfspath, NULL, NULL); > + if (rc == 0) { > + cifs_dbg(FYI, "DFS ref '%s' is found, emulate -EREMOTE\n", > + dfspath); > + rc = -EREMOTE; > + } else if (rc == -EEXIST) { > + cifs_dbg(FYI, "DFS ref '%s' is not found, emulate -ENOENT\n", > + dfspath); > + rc = -ENOENT; > + } else { > + cifs_dbg(FYI, "%s: dfs_cache_find returned %d\n", __func__, rc); > + } > + kfree(dfspath); > + return rc; > +} > #endif > -- > 2.30.2 > -- Thanks, Steve
