Package: libsane
Version: 1.0.25-2
Severity: important
Dear Maintainer,
even a trivial program that uses sane_init, sane_get_devices, and sane_exit in
a loop, crashes with SIGSEGV
in the moment that a change on the device list occurs.
I.e. the following program crashes when you switch on or off a scanner after
you started it:
#include <sane/sane.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main (int argc, char **argv) {
while (1) {
if (sane_init(0, 0) != SANE_STATUS_GOOD)
exit (1);
const SANE_Device ** device_list;
if (sane_get_devices (&device_list, 1) == SANE_STATUS_GOOD) {
const SANE_Device **dev = device_list;
while (*dev)
dev++;
printf ("Device count: %d\n", dev - device_list);
} else {
fputs ("Failed sane_get_devices\n", stderr);
}
sleep (1);
sane_exit();
sleep (1);
}
}
The result seems to be a heavy memory corruption, at least I could not get any
sensible information from
a core dump produced.
I get the same behaviour with two different backends, epson2 and the
epkowa/iscan2 provided by Epson.
In practice, this is what occurs to scanbd, only that this is a much more
complicated piece of software.
I would have expected that this program runs slow and inefficient, but stable,
and presents an up-to-date
number of switched-on, connected scanners.
A finding that might be related or a different bug on its own is, that the list
returned by sane_get_devices
does never change if you do not call sane_init/sane_exit in the loop. This is
at least a difference to the
documented behaviour.
In summary, it appears impossible to write a program that presents an
up-to-date scanner device list without
restarting itself..?
Yours,
Andreas.
-- System Information:
Debian Release: stretch/sid
APT prefers testing
APT policy: (990, 'testing'), (500, 'unstable'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 4.3.0-1-amd64 (SMP w/1 CPU core)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)
Versions of packages libsane depends on:
ii acl 2.2.52-2
ii adduser 3.113+nmu3
ii libavahi-client3 0.6.32~rc+dfsg-1
ii libavahi-common3 0.6.32~rc+dfsg-1
ii libc6 2.21-7
ii libexif12 0.6.21-2
ii libgphoto2-6 2.5.9-3
ii libgphoto2-port12 2.5.9-3
ii libieee1284-3 0.2.11-12
ii libjpeg62-turbo 1:1.4.1-2
ii libsane-common 1.0.25-2
ii libtiff5 4.0.6-1
ii libusb-1.0-0 2:1.0.20-1
ii makedev 2.3.1-93
ii udev 228-4+b1
Versions of packages libsane recommends:
ii libsane-extras 1.0.22.3
ii sane-utils 1.0.25-2
Versions of packages libsane suggests:
ii avahi-daemon 0.6.32~rc+dfsg-1
pn hplip <none>
-- no debconf information
