From: Vincent Lefevre <vincent@vinc17.net>
To: libc-alpha@sourceware.org
Subject: Re: UB status of snprintf on invalid ptr+size combination?
Date: Mon, 20 Mar 2023 17:33:19 +0100 [thread overview]
Message-ID: <20230320163319.GF203866@cventin.lip.ens-lyon.fr> (raw)
In-Reply-To: <ba3499ce-f296-5368-e9ed-f55526fb4b07@gmail.com>
On 2023-03-20 17:15:49 +0100, Alejandro Colomar wrote:
> $ cat str.c
> #include <stdio.h>
>
> void f(char *dst, char *src)
> {
> sprintf(dst, "%s plus some extra stuff", src);
> }
>
> $ cat main.c
> void f(char *dst, char *src);
>
> int main(void)
> {
> char *str = "some long string";
> char s[20];
>
> f(s, str);
> }
>
> $ cc -Wall -Wextra *.c -flto -O3 -fanalyzer -D_FORTIFY_SOURCE=1
> $ ./a.out
> *** buffer overflow detected ***: terminated
> Aborted
> $ cc -Wall -Wextra *.c -flto -O3 -fanalyzer -D_FORTIFY_SOURCE=3
> alx@asus5775:~/tmp/fort$ ./a.out
> *** buffer overflow detected ***: terminated
> Aborted
>
>
> Is this what you're looking for? I agree that it would be nicer
> if the analyzer could catch this at build time, but it seems it's
> not yet so powerful.
I meant at build time.
--
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
next prev parent reply other threads:[~2023-03-20 16:33 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-14 19:47 Simon Chopin
2023-03-14 21:39 ` Paul Eggert
2023-03-15 9:22 ` Andreas Schwab
2023-03-15 15:54 ` Siddhesh Poyarekar
2023-03-15 18:34 ` Michael Hudson-Doyle
2023-03-19 14:45 ` manfred
2023-03-19 23:07 ` Vincent Lefevre
2023-03-20 12:05 ` Siddhesh Poyarekar
2023-03-20 12:17 ` Alejandro Colomar
2023-03-20 12:29 ` Siddhesh Poyarekar
2023-03-20 13:36 ` Vincent Lefevre
2023-03-20 13:50 ` Vincent Lefevre
2023-03-20 16:56 ` Siddhesh Poyarekar
2023-03-20 17:36 ` Vincent Lefevre
2023-03-20 15:09 ` Vincent Lefevre
2023-03-20 16:15 ` Alejandro Colomar
2023-03-20 16:33 ` Vincent Lefevre [this message]
2023-03-20 17:00 ` Vincent Lefevre
2023-03-20 17:31 ` Siddhesh Poyarekar
2023-03-20 17:45 ` Vincent Lefevre
2023-03-15 12:39 ` Vincent Lefevre
2023-03-16 10:29 ` Stephan Bergmann
2023-03-18 2:07 ` Vincent Lefevre
2023-03-18 2:30 ` Alejandro Colomar
2023-03-18 10:58 ` Vincent Lefevre
2023-03-18 15:01 ` Andreas Schwab
2023-03-19 22:48 ` Vincent Lefevre
2023-03-19 23:24 ` Andreas Schwab
2023-03-20 4:10 ` Vincent Lefevre
2023-03-20 9:19 ` Andreas Schwab
2023-03-20 10:42 ` Vincent Lefevre
2023-03-20 10:44 ` Andreas Schwab
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