This looks a lot like #1783110 ** Information type changed from Private Security to Public
** Information type changed from Public to Private Security ** Information type changed from Private Security to Public Security -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1791893 Title: Trailing garbage data when sending on an AF_PACKET socket Status in linux package in Ubuntu: New Bug description: When sending an Ethernet frame on an packet socket (AF_PACKET, SOCK_RAW), an additional 14 bytes of trailing data is sent on the interface. The extra 14 bytes are present regardless of the packet size. The extra data could be garbage/uninitialised kernel memory. Expected result: The raw Ethernet frame is sent on the interface. Actual result: The raw Ethernet frame plus an additional 14 bytes of unknown data is sent on the interface. Steps to reproduce: The attached test program inject.c can be used to reproduce the issue. # In window 1. Send an EAP packet without any payload. gcc inject.c -o inject sudo ./inject lo # Simultaneously in window 2. Tcpdump shows a payload of 14 bytes. sudo tcpdump -i lo -enlx 07:45:45.005652 02:00:00:00:00:01 > 02:00:00:00:00:00, ethertype EAPOL (0x888e), length 28: EAP packet (0) v64, len 0 0x0000: 4000 0000 0000 0000 4000 0000 0000 Running strace on the "inject" program shows that send(2) is indeed called with the correct buffer size. The extra 14 bytes appear to be added by the kernel, and this might leak kernel memory. Ubuntu release: Ubuntu 18.04.1 LTS Package version: 4.15.0-33.36 The issue could not be reproduced on linux-image-4.15.0-22-generic or linux-image-4.15.0-23-generic. uname -a: Linux ubuntu 4.15.0-33-generic #36-Ubuntu SMP Wed Aug 15 16:00:05 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1791893/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
