一、漏洞信息
漏洞编号：CVE-2022-48644
漏洞归属组件：kernel
漏洞归属的版本：4.19.140,4.19.194,4.19.90,5.10.0,6.1.0,6.1.14,6.1.19,6.1.5,6.1.6,6.1.8,6.4.0,6.6.0
CVSS V2.0分值：
BaseScore：0.0 Medium
Vector：CVSS：2.0/
漏洞简述：
In the Linux kernel, the following vulnerability has been resolved:net/sched: taprio: avoid disabling offload when it was never enabledIn an incredibly strange API design decision, qdisc->destroy() getscalled even if qdisc->init() never succeeded, not exclusively sincecommit 87b60cfacf9f ( net_sched: fix error recovery at qdisc creation ),but apparently also earlier (in the case of qdisc_create_dflt()).The taprio qdisc does not fully acknowledge this when it attempts fulloffload, because it starts off with q->flags = TAPRIO_FLAGS_INVALID intaprio_init(), then it replaces q->flags with TCA_TAPRIO_ATTR_FLAGSparsed from netlink (in taprio_change(), tail called from taprio_init()).But in taprio_destroy(), we call taprio_disable_offload(), and thisdetermines what to do based on FULL_OFFLOAD_IS_ENABLED(q->flags).But looking at the implementation of FULL_OFFLOAD_IS_ENABLED()(a bitwise check of bit 1 in q->flags), it is invalid to call this macroon q->flags when it contains TAPRIO_FLAGS_INVALID, because that is setto U32_MAX, and therefore FULL_OFFLOAD_IS_ENABLED() will return true onan invalid set of flags.As a result, it is possible to crash the kernel if user space forces anerror between setting q->flags = TAPRIO_FLAGS_INVALID, and the callingof taprio_enable_offload(). This is because drivers do not expect theoffload to be disabled when it was never enabled.The error that we force here is to attach taprio as a non-root qdisc,but instead as child of an mqprio root qdisc:$ tc qdisc add dev swp0 root handle 1: mqprio num_tc 8 map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 hw 0$ tc qdisc replace dev swp0 parent 1:1 taprio num_tc 8 map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 0 sched-entry S 0x7f 990000 sched-entry S 0x80 100000 flags 0x0 clockid CLOCK_TAIUnable to handle kernel paging request at virtual address fffffffffffffff8[fffffffffffffff8] pgd=0000000000000000, p4d=0000000000000000Internal error: Oops: 96000004 [#1] PREEMPT SMPCall trace: taprio_dump+0x27c/0x310 vsc9959_port_setup_tc+0x1f4/0x460 felix_port_setup_tc+0x24/0x3c dsa_slave_setup_tc+0x54/0x27c taprio_disable_offload.isra.0+0x58/0xe0 taprio_destroy+0x80/0x104 qdisc_create+0x240/0x470 tc_modify_qdisc+0x1fc/0x6b0 rtnetlink_rcv_msg+0x12c/0x390 netlink_rcv_skb+0x5c/0x130 rtnetlink_rcv+0x1c/0x2cFix this by keeping track of the operations we made, and undo theoffload only if we actually did it.I ve added bool offloaded inside a 4 byte hole between int clockid and atomic64_t picos_per_byte . Now the first cache line looks likebelow:$ pahole -C taprio_sched net/sched/sch_taprio.ostruct taprio_sched { struct Qdisc * * qdiscs; /* 0 8 / struct Qdisc * root; / 8 8 / u32 flags; / 16 4 / enum tk_offsets tk_offset; / 20 4 / int clockid; / 24 4 / bool offloaded; / 28 1 / / XXX 3 bytes hole, try to pack / atomic64_t picos_per_byte; / 32 0 / / XXX 8 bytes hole, try to pack / spinlock_t current_entry_lock; / 40 0 / / XXX 8 bytes hole, try to pack / struct sched_entry * current_entry; / 48 8 / struct sched_gate_list * oper_sched; / 56 8 / / --- cacheline 1 boundary (64 bytes) --- */
漏洞公开时间：2024-04-28 21:15:07
漏洞创建时间：2024-04-28 22:59:06
漏洞详情参考链接：
https://nvd.nist.gov/vuln/detail/CVE-2022-48644

漏洞分析指导链接：
https://gitee.com/openeuler/cve-manager/blob/master/cve-vulner-manager/doc/md/manual.md
漏洞数据来源:
openBrain开源漏洞感知系统
漏洞补丁信息：

二、漏洞分析结构反馈
影响性分析说明：
Reserved.
openEuler评分：
4.0
Vector：CVSS：2.0/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:N
受影响版本排查(受影响/不受影响)：
1.openEuler-22.03-LTS-SP1(5.10.0):受影响
2.openEuler-20.03-LTS-SP4(4.19.90):不受影响
3.openEuler-22.03-LTS-SP3(5.10.0):不受影响
4.openEuler-22.03-LTS-SP4(5.10.0):不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS(6.6.0):不受影响
7.openEuler-24.03-LTS-Next(6.6.0):不受影响

修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4(4.19.90):否
2.openEuler-22.03-LTS-SP1(5.10.0):否
3.openEuler-22.03-LTS-SP3(5.10.0):否
4.master(6.1.0):否
5.openEuler-24.03-LTS(6.6.0):否
6.openEuler-24.03-LTS-Next(6.6.0):否
7.openEuler-22.03-LTS-SP4(5.10.0):否

三、漏洞修复
安全公告链接：https://www.openeuler.org/zh/security/safety-bulletin/detail/?id=openEuler-SA-2024-2080