From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin-apps@cygwin.com
Subject: Re: [PATCH setup] Avoid stringop-overflow warning with gcc8
Date: Fri, 12 Oct 2018 15:58:00 -0000 [thread overview]
Message-ID: <20181012155839.GG7872@calimero.vinschen.de> (raw)
In-Reply-To: <20181012154349.46104-1-jon.turney@dronecode.org.uk>
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On Oct 12 16:43, Jon Turney wrote:
> desktop.cc: In function 'void start_menu(const string&, const string&, const string&, const string&)':
> desktop.cc:110:11: error: 'char* strncat(char*, const char*, size_t)' specified bound 260 equals destination size [-Werror=stringop-overflow=]
>
> I think strlcat() was meant here, which MinGW doesn't have. In it's
> absence, open-code it's equivalent.
>
> (SHGetSpecialFolderLocation() returns a pathname of length at most MAX_PATH,
> and make_link() is limited to accepting a pathname of length MAX_PATH, so we
> want to append our folder name, while truncating the result to MAX_PATH.)
> ---
> desktop.cc | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/desktop.cc b/desktop.cc
> index 927c02f..d003e91 100644
> --- a/desktop.cc
> +++ b/desktop.cc
> @@ -107,7 +107,8 @@ start_menu (const std::string& title, const std::string& target,
> issystem ? CSIDL_COMMON_PROGRAMS :
> CSIDL_PROGRAMS, &id);
> SHGetPathFromIDList (id, path);
> - strncat (path, "/Cygwin", MAX_PATH);
> + strncat (path, "/Cygwin", MAX_PATH - strlen(path));
Shouldn't that be
strncat (path, "/Cygwin", MAX_PATH - strlen(path) - 1);
?
"If src contains n or more bytes, strncat() writes n+1 bytes to dest (n
from src plus the terminating null byte). Therefore, the size of dest
must be at least strlen(dest)+n+1."
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
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next prev parent reply other threads:[~2018-10-12 15:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-12 15:44 Jon Turney
2018-10-12 15:58 ` Corinna Vinschen [this message]
2018-10-13 12:50 ` Jon Turney
2018-10-13 14:36 ` Corinna Vinschen
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