FS#15363 - [wireless_tools] iwlist scan : print_scanning_info: Allocation failed

Attached to Project: Arch Linux
Opened by Amine Haddad (aminehaddad) - Saturday, 04 July 2009, 09:22 GMT
Last edited by Gaetan Bisson (vesath) - Monday, 20 August 2012, 14:55 GMT
Task Type Bug Report
Category Upstream Bugs
Status Closed
Assigned To Gaetan Bisson (vesath)
Architecture All
Severity Medium
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No

Details

Description: When you are in a dense wireless environment (100+ access points, such as my university), you cannot connect to any wireless networks using wicd or network-manager or even iwconfig because they depend on the result of 'iwlist scan'. When storing results of a scan, iwlist starts with a buffer of size 4096 and doubles whenever it needs more space (4096, 8192, 16384, 32768, 65536). The problem is that the maximum allowed is 65535, but it can only double to 65536. To fix the issue, just check if the length of the buffer is over 65535 and if it is then set it to 65535.

Attachments:
* iwlist-print-scanning-info-allocation-failed.patch - the patch to fix the current version in core
* wireless_tools-makepkg.zip - a working PKGBUILD for those interested in applying the patch immediately (http://wiki.archlinux.org/index.php/Makepkg#Building_a_Package)

Additional info:
* affects wireless_tools version 29-3
* original report: http://www.intellinuxwireless.org/bugzilla/show_bug.cgi?id=1885

Steps to reproduce:
* run 'iwlist scan' in an area with a lot of wireless access points (100+)

Output:
* print_scanning_info: Allocation failed
   iwlist-print-scanning-info-al... (0.7 KiB)
   wireless_tools-makepkg.zip (1.6 KiB)
This task depends upon

Closed by  Gaetan Bisson (vesath)
Monday, 20 August 2012, 14:55 GMT
Reason for closing:  Fixed
Additional comments about closing:  wireless_tools-29-7 in [testing]
Comment by Ju Liu (Arkham) - Sunday, 04 October 2009, 00:16 GMT
How is this archlinux related? It definitely seems an upstream limitation.
Comment by Markus (fixje) - Monday, 20 August 2012, 10:43 GMT
  • Field changed: Percent Complete (100% → 0%)
The bug still exists in 29-6 and has been reported upstream. The original author didn't respond for weeks, now. Maybe the packager should consider to apply the attached patch before packaging.
Comment by Jan de Groot (JGC) - Monday, 20 August 2012, 10:45 GMT
Attached patch fixes a bug that makes association impossible in dense networks. Version 30-pre9 contains a modified version of the patch, they use 0xFFFF hex notation instead of 65535.

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