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Bug#517714: marked as done (glibc: possible signed integer overflow in libio/iogetdelim.c)

Your message dated Thu, 24 Apr 2014 17:55:51 +0200
with message-id <20140424155551.GA10616@free.fr>
and subject line glibc: possible signed integer overflow in libio/iogetdelim.c
has caused the Debian Bug report #517714,
regarding glibc: possible signed integer overflow in libio/iogetdelim.c
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

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-- 
517714: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=517714
Debian Bug Tracking System
Contact owner@bugs.debian.org with problems
--- Begin Message --- 
Package: libc6
Version: 2.9-3
Severity: minor

An excerpt from gcc manual page:

  -fstrict-overflow
Allow the compiler to assume strict signed overflow rules, depending on the language being compiled. For C (and C++) this means that overflow when doing arithmetic with signed numbers is undefined, which means that the compiler may assume that it will not happen. [...] When this option is in effect any attempt to determine whether an operation on signed numbers will overflow must be written carefully to not actually involve overflow. 
  [...]
  The -fstrict-overflow option is enabled at levels -O2, -O3, -Os.

(Note that glibc is compiled with -O2 in Debian.)
I guess the following code snippet from libio/iogetdelim.c could serve as an example how *not* to write code, when this option is turned on: 

  if (__builtin_expect (cur_len + len + 1 < 0, 0))
    {
      __set_errno (EOVERFLOW);
      result = -1;
      goto unlock_return;
    }

--
Jakub Wilk

--- End Message ---
--- Begin Message --- 
fixed 517714 eglibc/2.17-0experimental0
stop

See https://sourceware.org/bugzilla/show_bug.cgi?id=9914#c12

-- 
Stéphane Aulery

--- End Message ---
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