Executive Summary
Informations | |||
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Name | CVE-2022-48644 | First vendor Publication | 2024-04-28 |
Vendor | Cve | Last vendor Modification | 2024-04-29 |
Security-Database Scoring CVSS v3
Cvss vector : N/A | |||
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Overall CVSS Score | NA | ||
Base Score | NA | Environmental Score | NA |
impact SubScore | NA | Temporal Score | NA |
Exploitabality Sub Score | NA | ||
Calculate full CVSS 3.0 Vectors scores |
Security-Database Scoring CVSS v2
Cvss vector : | |||
---|---|---|---|
Cvss Base Score | N/A | Attack Range | N/A |
Cvss Impact Score | N/A | Attack Complexity | N/A |
Cvss Expoit Score | N/A | Authentication | N/A |
Calculate full CVSS 2.0 Vectors scores |
Detail
In the Linux kernel, the following vulnerability has been resolved: net/sched: taprio: avoid disabling offload when it was never enabled In an incredibly strange API design decision, qdisc->destroy() gets called even if qdisc->init() never succeeded, not exclusively since commit 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 full offload, because it starts off with q->flags = TAPRIO_FLAGS_INVALID in taprio_init(), then it replaces q->flags with TCA_TAPRIO_ATTR_FLAGS parsed from netlink (in taprio_change(), tail called from taprio_init()). But in taprio_destroy(), we call taprio_disable_offload(), and this determines 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 macro on q->flags when it contains TAPRIO_FLAGS_INVALID, because that is set to U32_MAX, and therefore FULL_OFFLOAD_IS_ENABLED() will return true on an invalid set of flags. As a result, it is possible to crash the kernel if user space forces an error between setting q->flags = TAPRIO_FLAGS_INVALID, and the calling of taprio_enable_offload(). This is because drivers do not expect the offload 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: \ Fix this by keeping track of the operations we made, and undo the offload 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 like below: $ pahole -C taprio_sched net/sched/sch_taprio.o struct taprio_sched { /* 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 */ |
Original Source
Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-48644 |
Sources (Detail)
Alert History
Date | Informations |
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2024-04-29 17:27:26 |
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2024-04-28 17:27:28 |
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