Hi All,
We found a bug in the `head' program of coreutils 8.20:
Invoking `head -c -P' or `head -c -E' will cause memory exhaustion.
However, smaller units (e.g., b, K, M) work fine; bigger units (e.g., Z, Y)
fail properly
(by outputing "number of bytes is so large that it is not representable").
And `-n' also
works fine.
A bit dig reveals that the bug is introduced at line 322 of head.c
(coreutils 8.20):
204: elide_tail_bytes_pipe (const char *filename, int fd, uintmax_t
n_elide_0)
205: {
322: b = xcalloc (n_bufs, sizeof *b); /** this statement fails **/
398: }
We also examined n_elide and n_bufs before that statement. Actually, they
are very
large:
n_elide: 1125899906842624
n_bufs: 137438953474
According to the following comment in the source file:
> CAUTION: do not fail (out of memory) when asked to elide
> a ridiculous amount, but when given only a small input. */
We think this is a bug and bring this issue to your attention. Thanks!
Environments:
$ uname -a
Linux anti-think 3.7.3-1-ARCH #1 SMP PREEMPT Thu Jan 17 18:52:30 CET 2013
x86_64 GNU/Linux
$ pacman -Qi coreutils
Name : coreutils
Version : 8.20-1
URL : http://www.gnu.org/software/coreutils
Licenses : GPL3
Groups : base
Provides : None
Depends On : glibc pam acl gmp libcap
Optional Deps : None
Required By : ca-certificates dbus filesystem linux mkinitcpio perl
sysvinit-tools util-linux
Conflicts With : None
Replaces : None
Installed Size : 13820.00 KiB
Packager : Allan McRae <al...@archlinux.org>
Architecture : x86_64
Build Date : Wed 24 Oct 2012 03:57:11 AM EDT
Install Date : Sun 28 Oct 2012 01:51:06 PM EDT
Install Reason : Explicitly installed
Install Script : Yes
Description : The basic file, shell and text manipulation utilities of
the GNU operating system
CPU: Intel(R) Core(TM) i5-3320M CPU @ 2.60GHz CPU
memory: 4GB
Best regards,
--
Lei Zhang
Department of Electrical and Computer Engineering
University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
