From 859057cc97cc949b0097cd1e776a6708b367e99c Mon Sep 17 00:00:00 2001 From: Thiago Rafael Becker Date: Wed, 15 Dec 2021 00:08:31 -0300 Subject: [PATCH] cifs: sanitize multiple delimiters in prepath mount.cifs can pass a device with multiple delimiters in it. This will cause rename(2) to fail with ENOENT. BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2031200 Fixes: 24e0a1eff9e2 ("cifs: switch to new mount api") Cc: stable@vger.kernel.org # 5.11+ Acked-by: Ronnie Sahlberg Signed-off-by: Thiago Rafael Becker Signed-off-by: Steve French --- fs/cifs/fs_context.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c index 6a179ae753c1..4ce8a7df3a02 100644 --- a/fs/cifs/fs_context.c +++ b/fs/cifs/fs_context.c @@ -434,6 +434,34 @@ int smb3_parse_opt(const char *options, const char *key, char **val) return rc; } +/* + * remove duplicate path delimiters. Windows is supposed to do that + * but there are some bugs that prevent rename from working if there are + * multiple delimiters. + */ +void sanitize_path(char *path) +{ + char *pos = path, last = *path; + unsigned int offset = 0; + + while (*(++pos)) { + if ((*pos == '/' || *pos == '\\') && (last == '/' || last == '\\')) { + offset++; + continue; + } + last = *pos; + *(pos - offset) = *pos; + } + + pos = pos - offset - 1; + + /* At this point, there should be only zero or one delimiter at the end of the string */ + if (*pos != '/' && *pos != '\\') + pos++; + + *pos = '\0'; +} + /* * Parse a devname into substrings and populate the ctx->UNC and ctx->prepath * fields with the result. Returns 0 on success and an error otherwise @@ -497,6 +525,8 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx) if (!ctx->prepath) return -ENOMEM; + sanitize_path(ctx->prepath); + return 0; } -- 2.32.0