Описание
In the Linux kernel, the following vulnerability has been resolved:
net: spacemit: clear TX descriptor on fragment mapping failure
emac_tx_mem_map() writes TX_DESC_0_OWN into the ring descriptor for
every slot beyond old_head as soon as that slot's memset()'d local
copy is committed with "*tx_desc_addr = tx_desc", i.e. before the
buffers for that slot have necessarily all been mapped successfully.
If emac_tx_map_frag() then fails on a later fragment, the err_free_skb
path calls emac_free_tx_buf() to unmap and drop the skb, but leaves
the already-written descriptor memory untouched, and tx_ring->head is
never advanced past old_head (the "tx_ring->head = head" store is
skipped by the goto).
So a slot between old_head and the rolled-back head can be left with
TX_DESC_0_OWN set and buffer_addr_{1,2} pointing at DMA mappings that
emac_free_tx_buf() just tore down, while software considers that slot
free again. The next successful emac_tx_mem_map() call only rebuilds
old_head itself; if the DMA engine auto-advances into the following
descriptor once it finishes old_head's packet, it will fetch that
stale, already-unmapped address.
emac_tx_clean_desc() already treats emac_free_tx_buf() and clearing
the descriptor as a pair when reclaiming completed descriptors; do
the same in the mapping failure path.
A flaw was found in the Linux kernel's SpacemiT Ethernet driver. During network packet transmission, a failure to map packet fragments causes the driver to release memory buffers without properly clearing the corresponding hardware descriptors. A local user able to trigger transmission mapping errors can cause the network controller's Direct Memory Access (DMA) engine to access unmapped memory, potentially resulting in memory corruption or a Denial of Service (DoS) through a system crash.
Отчет
This vulnerability is rated Moderate for Red Hat environments because exploitation requires local access and the presence of specific SpacemiT network hardware, which is absent from typical enterprise deployments. Impact is largely confined to specialized embedded and automotive systems running platforms equipped with the SpacemiT network architecture. Although an authenticated local actor capable of inducing memory mapping failures during packet processing could cause the DMA controller to reference released memory, resulting in a system crash or kernel instability, the prerequisite conditions and specialized hardware substantially restrict the threat.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected |
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Дополнительная информация
Статус:
4.7 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: net: spacemit: clear TX descriptor on fragment mapping failure emac_tx_mem_map() writes TX_DESC_0_OWN into the ring descriptor for every slot beyond old_head as soon as that slot's memset()'d local copy is committed with "*tx_desc_addr = tx_desc", i.e. before the buffers for that slot have necessarily all been mapped successfully. If emac_tx_map_frag() then fails on a later fragment, the err_free_skb path calls emac_free_tx_buf() to unmap and drop the skb, but leaves the already-written descriptor memory untouched, and tx_ring->head is never advanced past old_head (the "tx_ring->head = head" store is skipped by the goto). So a slot between old_head and the rolled-back head can be left with TX_DESC_0_OWN set and buffer_addr_{1,2} pointing at DMA mappings that emac_free_tx_buf() just tore down, while software considers that slot free again. The next successful emac_tx_mem_map() call only rebuilds old_head itself; if t...
In the Linux kernel, the following vulnerability has been resolved: net: spacemit: clear TX descriptor on fragment mapping failure emac_tx_mem_map() writes TX_DESC_0_OWN into the ring descriptor for every slot beyond old_head as soon as that slot's memset()'d local copy is committed with "*tx_desc_addr = tx_desc", i.e. before the buffers for that slot have necessarily all been mapped successfully. If emac_tx_map_frag() then fails on a later fragment, the err_free_skb path calls emac_free_tx_buf() to unmap and drop the skb, but leaves the already-written descriptor memory untouched, and tx_ring->head is never advanced past old_head (the "tx_ring->head = head" store is skipped by the goto). So a slot between old_head and the rolled-back head can be left with TX_DESC_0_OWN set and buffer_addr_{1,2} pointing at DMA mappings that emac_free_tx_buf() just tore down, while software considers that slot free again. The next successful emac_tx_mem_map() call only rebuilds old_head itself; if t
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: net: spacemit: clear TX descriptor on fragment mapping failure emac_tx_mem_map() writes TX_DESC_0_OWN into the ring descriptor for every slot beyond old_head as soon as that slot's memset()'d local copy is committed with "*tx_desc_addr = tx_desc", i.e. before the buffers for that slot have necessarily all been mapped successfully. If emac_tx_map_frag() then fails on a later fragment, the err_free_skb path calls emac_free_tx_buf() to unmap and drop the skb, but leaves the already-written descriptor memory untouched, and tx_ring->head is never advanced past old_head (the "tx_ring->head = head" store is skipped by the goto). So a slot between old_head and the rolled-back head can be left with TX_DESC_0_OWN set and buffer_addr_{1,2} pointing at DMA mappings that emac_free_tx_buf() just tore down, while software considers that slot free again. The next successful emac_tx_mem_map() call only rebuilds old_head itself; i...
4.7 Medium
CVSS3