CVE-2021-47562 (Moderate severity, published 2024-05-23)
CVSS score: 5.3 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H)
CWE: CWE-476
Description: In the Linux kernel, the following vulnerability has been resolved:

ice: fix vsi->txq_map sizing

The approach of having XDP queue per CPU regardless of user's setting
exposed a hidden bug that could occur in case when Rx queue count differ
from Tx queue count. Currently vsi->txq_map's size is equal to the
doubled vsi->alloc_txq, which is not correct due to the fact that XDP
rings were previously based on the Rx queue count. Below splat can be
seen when ethtool -L is used and XDP rings are configured:

[  682.875339] BUG: kernel NULL pointer dereference, address: 000000000000000f
[  682.883403] #PF: supervisor read access in kernel mode
[  682.889345] #PF: error_code(0x0000) - not-present page
[  682.895289] PGD 0 P4D 0
[  682.898218] Oops: 0000 [#1] PREEMPT SMP PTI
[  682.903055] CPU: 42 PID: 2878 Comm: ethtool Tainted: G           OE     5.15.0-rc5+ #1
[  682.912214] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016
[  682.923380] RIP: 0010:devres_remove+0x44/0x130
[  682.928527] Code: 49 89 f4 55 48 89 fd 4c 89 ff 53 48 83 ec 10 e8 92 b9 49 00 48 8b 9d a8 02 00 00 48 8d 8d a0 02 00 00 49 89 c2 48 39 cb 74 0f <4c> 3b 63 10 74 25 48 8b 5b 08 48 39 cb 75 f1 4c 89 ff 4c 89 d6 e8
[  682.950237] RSP: 0018:ffffc90006a679f0 EFLAGS: 00010002
[  682.956285] RAX: 0000000000000286 RBX: ffffffffffffffff RCX: ffff88908343a370
[  682.964538] RDX: 0000000000000001 RSI: ffffffff81690d60 RDI: 0000000000000000
[  682.972789] RBP: ffff88908343a0d0 R08: 0000000000000000 R09: 0000000000000000
[  682.981040] R10: 0000000000000286 R11: 3fffffffffffffff R12: ffffffff81690d60
[  682.989282] R13: ffffffff81690a00 R14: ffff8890819807a8 R15: ffff88908343a36c
[  682.997535] FS:  00007f08c7bfa740(0000) GS:ffff88a03fd00000(0000) knlGS:0000000000000000
[  683.006910] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  683.013557] CR2: 000000000000000f CR3: 0000001080a66003 CR4: 00000000003706e0
[  683.021819] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  683.030075] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  683.038336] Call Trace:
[  683.041167]  devm_kfree+0x33/0x50
[  683.045004]  ice_vsi_free_arrays+0x5e/0xc0 [ice]
[  683.050380]  ice_vsi_rebuild+0x4c8/0x750 [ice]
[  683.055543]  ice_vsi_recfg_qs+0x9a/0x110 [ice]
[  683.060697]  ice_set_channels+0x14f/0x290 [ice]
[  683.065962]  ethnl_set_channels+0x333/0x3f0
[  683.070807]  genl_family_rcv_msg_doit+0xea/0x150
[  683.076152]  genl_rcv_msg+0xde/0x1d0
[  683.080289]  ? channels_prepare_data+0x60/0x60
[  683.085432]  ? genl_get_cmd+0xd0/0xd0
[  683.089667]  netlink_rcv_skb+0x50/0xf0
[  683.094006]  genl_rcv+0x24/0x40
[  683.097638]  netlink_unicast+0x239/0x340
[  683.102177]  netlink_sendmsg+0x22e/0x470
[  683.106717]  sock_sendmsg+0x5e/0x60
[  683.110756]  __sys_sendto+0xee/0x150
[  683.114894]  ? handle_mm_fault+0xd0/0x2a0
[  683.119535]  ? do_user_addr_fault+0x1f3/0x690
[  683.134173]  __x64_sys_sendto+0x25/0x30
[  683.148231]  do_syscall_64+0x3b/0xc0
[  683.161992]  entry_SYSCALL_64_after_hwframe+0x44/0xae

Fix this by taking into account the value that num_possible_cpus()
yields in addition to vsi->alloc_txq instead of doubling the latter.
Mitigation: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.