Full Disclosure mailing list archives
Re: Python 2.5 (Modules/zlib) minigzip local buffer overflow vulnerability
From: Ismail Dönmez <ismail () pardus org tr>
Date: Fri, 16 Mar 2007 02:20:06 +0200
On Friday 16 March 2007 00:00:23 Ulf Harnhammar wrote:
Using strncpy is just strcpy + strlen anyway it can't have a big speed impact or anything.That's not really true. If you check the Linux manpage for strncpy(3), it says: char *strncpy(char *dest, const char *src, size_t n); [blah] In the case where the length of src is less than that of n, the remain- der of dest will be padded with null bytes. "The C Programming Language" agrees: "Pad with '\0's if t has fewer than n characters."
Argh I forgot about the NULL padding, you are correct.
Thus, replacing strcpy(3) calls with strncpy(3) can have definite impacts on performance.
But the question is how big impact? Its a security/speed trade-off. Regards. -- Happiness in intelligent people is the rarest thing I know. (Ernest Hemingway) Ismail Donmez ismail (at) pardus.org.tr GPG Fingerprint: 7ACD 5836 7827 5598 D721 DF0D 1A9D 257A 5B88 F54C Pardus Linux / KDE developer _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- Re: Python 2.5 (Modules/zlib) minigzip local buffer overflow vulnerability Ulf Harnhammar (Mar 15)
- Re: Python 2.5 (Modules/zlib) minigzip local buffer overflow vulnerability Ismail Dönmez (Mar 15)
- Re: Python 2.5 (Modules/zlib) minigzip local buffer overflow vulnerability Alejandro Barrera (Mar 15)
- Re: Python 2.5 (Modules/zlib) minigzip local buffer overflow vulnerability Ismail Dönmez (Mar 15)