In the Linux kernel, the following vulnerability has been resolved: ixgbe: do not configure xps for XDP queues netif_set_xps_queue() should not be called for an XDP Tx queue, since such queues are not netdev-exposed

Overview

In the Linux kernel, the following vulnerability has been resolved:

ixgbe: do not configure xps for XDP queues

netif_set_xps_queue() should not be called for an XDP Tx queue, since such queues are not netdev-exposed. On systems with number of CPUs >=64, on E610 adapter, netdev is configured with maximum number queue pairs being 63 (due to MSI-X assignment), but configuring XDP results in 64 XDP queues.

So, during XDP program load, when netif_set_xps_queue() is called for the last XDP queue, we get a WARNING with a call trace and KASAN report afterwards (if enabled).

[ 2012.699800] WARNING: net/core/dev.c:2854 at __netif_set_xps_queue+0x116a/0x1e40, CPU#36: xdpsock/103668 [...] [ 2012.700029] RIP: 0010:__netif_set_xps_queue+0x116a/0x1e40 [ 2012.700035] Code: b6 34 06 48 89 f8 83 e0 07 83 c0 01 40 38 f0 7c 09 40 84 f6 0f 85 03 0a 00 00 0f b7 44 24 40 66 43 89 44 6a 18 e9 01 fb ff ff <0f> 0b e9 f2 ee ff ff 44 8b 44 24 44 45 85 c0 74 50 4d 85 e4 0f 84 [ 2012.700040] RSP: 0018:ffff8882369aeb28 EFLAGS: 00010246 [ 2012.700046] RAX: 0000000000000000 RBX: 000000000000003f RCX: 0000000000000000 [ 2012.700050] RDX: 1ffff1111da3d891 RSI: ffff888120e34250 RDI: ffff8888ed1ec488 [ 2012.700054] RBP: ffff888913281560 R08: 0000000000000000 R09: ffff8888ed1ec000 [ 2012.700058] R10: ffff8888a2e83180 R11: 0000000000000000 R12: 0000000000007fa8 [ 2012.700061] R13: 000000000000003f R14: ffff888120e34854 R15: ffff8889132817c8 [ 2012.700065] FS: 00007fc8ea9ff740(0000) GS:ffff88884cefe000(0000) knlGS:0000000000000000 [ 2012.700069] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2012.700073] CR2: 00007f81c8000020 CR3: 00000002299f8006 CR4: 00000000007726f0 [ 2012.700077] PKRU: 55555554 [ 2012.700080] Call Trace: [ 2012.700084] <TASK> [ 2012.700087] ? ktime_get+0x61/0x150 [ 2012.700097] ? usleep_range_state+0x133/0x1b0 [ 2012.700108] ? __pfx_usleep_range_state+0x10/0x10 [ 2012.700114] netif_set_xps_queue+0x31/0x50 [ 2012.700119] ixgbe_configure_tx_ring+0x472/0x920 [ixgbe] [...] [ 2012.700486] ixgbe_xdp+0x38f/0x750 [ixgbe]

[...]

[ 2012.701094] BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue+0x1ac5/0x1e40 [ 2012.701100] Write of size 4 at addr ffff88888d43cff8 by task xdpsock/103668

Skip XPS configuration for XDP Tx queues.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.