If igb's SR-IOV and promiscuous mode are enabled and the interface receives a tag VLAN packet, this will result in a null pointer dereference. To fix this, we will backport upstream commit 31b24b95 to ensure that vlan_gro_receive is only used if vlans have been registered to the adapter structure. [ This fixes bugzilla entry 15582 -Eric Dumazet] It matters if CONFIG_PCI_IOV is enabled, e.g. grep -ir SRIOV drivers/net/igb/*. Upstream commit: http://git.kernel.org/linus/31b24b95 References: https://bugzilla.kernel.org/show_bug.cgi?id=15582
Statement: This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 4 and Red Hat Enterprise MRG as they did not include support for PCI I/O Virtualization (IOV). Future updates in Red Hat Enterprise Linux 5 and 6 may address this flaw.
Acknowledgements: Red Hat would like to thank Kosuke Tatsukawa for reporting this issue.
This issue has been addressed in following products: Red Hat Enterprise Linux 6 Via RHSA-2011:0007 https://rhn.redhat.com/errata/RHSA-2011-0007.html
This issue has been addressed in following products: Red Hat Enterprise Linux 5 Via RHSA-2011:0017 https://rhn.redhat.com/errata/RHSA-2011-0017.html