CVE-2022-50003

Published Jun 18, 2025

Last updated a year ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: ice: xsk: prohibit usage of non-balanced queue id Fix the following scenario: 1. ethtool -L $IFACE rx 8 tx 96 2. xdpsock -q 10 -t -z Above refers to a case where user would like to attach XSK socket in txonly mode at a queue id that does not have a corresponding Rx queue. At this moment ice's XSK logic is tightly bound to act on a "queue pair", e.g. both Tx and Rx queues at a given queue id are disabled/enabled and both of them will get XSK pool assigned, which is broken for the presented queue configuration. This results in the splat included at the bottom, which is basically an OOB access to Rx ring array. To fix this, allow using the ids only in scope of "combined" queues reported by ethtool. However, logic should be rewritten to allow such configurations later on, which would end up as a complete rewrite of the control path, so let us go with this temporary fix. [420160.558008] BUG: kernel NULL pointer dereference, address: 0000000000000082 [420160.566359] #PF: supervisor read access in kernel mode [420160.572657] #PF: error_code(0x0000) - not-present page [420160.579002] PGD 0 P4D 0 [420160.582756] Oops: 0000 [#1] PREEMPT SMP NOPTI [420160.588396] CPU: 10 PID: 21232 Comm: xdpsock Tainted: G OE 5.19.0-rc7+ #10 [420160.597893] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [420160.609894] RIP: 0010:ice_xsk_pool_setup+0x44/0x7d0 [ice] [420160.616968] Code: f3 48 83 ec 40 48 8b 4f 20 48 8b 3f 65 48 8b 04 25 28 00 00 00 48 89 44 24 38 31 c0 48 8d 04 ed 00 00 00 00 48 01 c1 48 8b 11 <0f> b7 92 82 00 00 00 48 85 d2 0f 84 2d 75 00 00 48 8d 72 ff 48 85 [420160.639421] RSP: 0018:ffffc9002d2afd48 EFLAGS: 00010282 [420160.646650] RAX: 0000000000000050 RBX: ffff88811d8bdd00 RCX: ffff888112c14ff8 [420160.655893] RDX: 0000000000000000 RSI: ffff88811d8bdd00 RDI: ffff888109861000 [420160.665166] RBP: 000000000000000a R08: 000000000000000a R09: 0000000000000000 [420160.674493] R10: 000000000000889f R11: 0000000000000000 R12: 000000000000000a [420160.683833] R13: 000000000000000a R14: 0000000000000000 R15: ffff888117611828 [420160.693211] FS: 00007fa869fc1f80(0000) GS:ffff8897e0880000(0000) knlGS:0000000000000000 [420160.703645] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [420160.711783] CR2: 0000000000000082 CR3: 00000001d076c001 CR4: 00000000007706e0 [420160.721399] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [420160.731045] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [420160.740707] PKRU: 55555554 [420160.745960] Call Trace: [420160.750962] <TASK> [420160.755597] ? kmalloc_large_node+0x79/0x90 [420160.762703] ? __kmalloc_node+0x3f5/0x4b0 [420160.769341] xp_assign_dev+0xfd/0x210 [420160.775661] ? shmem_file_read_iter+0x29a/0x420 [420160.782896] xsk_bind+0x152/0x490 [420160.788943] __sys_bind+0xd0/0x100 [420160.795097] ? exit_to_user_mode_prepare+0x20/0x120 [420160.802801] __x64_sys_bind+0x16/0x20 [420160.809298] do_syscall_64+0x38/0x90 [420160.815741] entry_SYSCALL_64_after_hwframe+0x63/0xcd [420160.823731] RIP: 0033:0x7fa86a0dd2fb [420160.830264] Code: c3 66 0f 1f 44 00 00 48 8b 15 69 8b 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb bc 0f 1f 44 00 00 f3 0f 1e fa b8 31 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d 8b 0c 00 f7 d8 64 89 01 48 [420160.855410] RSP: 002b:00007ffc1146f618 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 [420160.866366] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa86a0dd2fb [420160.876957] RDX: 0000000000000010 RSI: 00007ffc1146f680 RDI: 0000000000000003 [420160.887604] RBP: 000055d7113a0520 R08: 00007fa868fb8000 R09: 0000000080000000 [420160.898293] R10: 0000000000008001 R11: 0000000000000246 R12: 000055d7113a04e0 [420160.909038] R13: 000055d7113a0320 R14: 000000000000000a R15: 0000000000000000 [420160.919817] </TASK> [420160.925659] Modules linked in: ice(OE) af_packet binfmt_misc ---truncated---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163