Juergen Gross 6032046ec4 xen/netback: fix rx queue stall detection ... Commit 1d5d485239 ("xen-netback: require fewer guest Rx slots when not using GSO") introduced a security problem in netback, as an interface would only be regarded to be stalled if no slot is available in the rx queue ring page. In case the SKB at the head of the queued requests will need more than one rx slot and only one slot is free the stall detection logic will never trigger, as the test for that is only looking for at least one slot to be free. Fix that by testing for the needed number of slots instead of only one slot being available. In order to not have to take the rx queue lock that often, store the number of needed slots in the queue data. As all SKB dequeue operations happen in the rx queue kernel thread this is safe, as long as the number of needed slots is accessed via READ/WRITE_ONCE() only and updates are always done with the rx queue lock held. Add a small helper for obtaining the number of free slots. This is part of XSA-392 Fixes: 1d5d485239 ("xen-netback: require fewer guest Rx slots when not using GSO") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>		2021-12-16 08:42:56 +01:00
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Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
common.h	xen/netback: fix rx queue stall detection	2021-12-16 08:42:56 +01:00
hash.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
interface.c	net: xen: use eth_hw_addr_set()	2021-10-22 10:15:54 -07:00
netback.c	xen-netback: Remove redundant initialization of variable err	2021-10-15 11:02:36 +01:00
rx.c	xen/netback: fix rx queue stall detection	2021-12-16 08:42:56 +01:00
xenbus.c	xen-netback: Check for hotplug-status existence before watching	2021-04-13 15:24:14 -07:00