From 16b5f54e30c1ddec36bdf946a299b3254aace477 Mon Sep 17 00:00:00 2001 From: Atte Heikkilä Date: Thu, 15 Sep 2022 22:49:11 +0900 Subject: ksmbd: casefold utf-8 share names and fix ascii lowercase conversion MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit strtolower() corrupts all UTF-8 share names that have a byte in the C0 (À ISO8859-1) to DE (Þ ISO8859-1) range, since the non-ASCII part of ISO8859-1 is incompatible with UTF-8. Prevent this by checking that a byte is in the ASCII range with isascii(), before the conversion to lowercase with tolower(). Properly handle case-insensitivity of UTF-8 share names by casefolding them, but fallback to ASCII lowercase conversion on failure or if CONFIG_UNICODE is not set. Refactor to move the share name casefolding immediately after the share name extraction. Also, make the associated constness corrections. Signed-off-by: Atte Heikkilä Acked-by: Namjae Jeon Signed-off-by: Steve French --- fs/ksmbd/misc.c | 44 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 36 insertions(+), 8 deletions(-) (limited to 'fs/ksmbd/misc.c') diff --git a/fs/ksmbd/misc.c b/fs/ksmbd/misc.c index 364a0a463dfc..28459b1efaa8 100644 --- a/fs/ksmbd/misc.c +++ b/fs/ksmbd/misc.c @@ -7,6 +7,7 @@ #include #include #include +#include #include "misc.h" #include "smb_common.h" @@ -226,26 +227,53 @@ void ksmbd_conv_path_to_windows(char *path) strreplace(path, '/', '\\'); } +static char *casefold_sharename(struct unicode_map *um, const char *name) +{ + char *cf_name; + int cf_len; + + cf_name = kzalloc(KSMBD_REQ_MAX_SHARE_NAME, GFP_KERNEL); + if (!cf_name) + return ERR_PTR(-ENOMEM); + + if (IS_ENABLED(CONFIG_UNICODE) && um) { + const struct qstr q_name = {.name = name, .len = strlen(name)}; + + cf_len = utf8_casefold(um, &q_name, cf_name, + KSMBD_REQ_MAX_SHARE_NAME); + if (cf_len < 0) + goto out_ascii; + + return cf_name; + } + +out_ascii: + cf_len = strscpy(cf_name, name, KSMBD_REQ_MAX_SHARE_NAME); + if (cf_len < 0) { + kfree(cf_name); + return ERR_PTR(-E2BIG); + } + + for (; *cf_name; ++cf_name) + *cf_name = isascii(*cf_name) ? tolower(*cf_name) : *cf_name; + return cf_name - cf_len; +} + /** * ksmbd_extract_sharename() - get share name from tree connect request * @treename: buffer containing tree name and share name * * Return: share name on success, otherwise error */ -char *ksmbd_extract_sharename(char *treename) +char *ksmbd_extract_sharename(struct unicode_map *um, const char *treename) { - char *name = treename; - char *dst; - char *pos = strrchr(name, '\\'); + const char *name = treename, *pos = strrchr(name, '\\'); if (pos) name = (pos + 1); /* caller has to free the memory */ - dst = kstrdup(name, GFP_KERNEL); - if (!dst) - return ERR_PTR(-ENOMEM); - return dst; + return casefold_sharename(um, name); } /** -- cgit v1.2.3-70-g09d2