In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net: airoha: Fix DMA direction for NPU mailbox buffer<\/p>\n
airoha_npu_send_msg() always maps the mailbox buffer with DMA_TO_DEVICE,
\nbut some callers expect the NPU to write response data back into the
\nsame buffer:<\/p>\n
– airoha_npu_wlan_msg_get() (NPU_OP_GET): NPU writes response into
\n the buffer, then the caller reads it via memcpy()
\n– airoha_npu_ppe_stats_setup() (NPU_OP_SET): NPU writes back
\n npu_stats_addr field in the response<\/p>\n
On non-cache-coherent architectures like EN7581 (Cortex-A53 without
\nhardware cache coherency for NPU DMA), DMA_TO_DEVICE unmap is a no-op
\n\u2014 it does not invalidate the CPU cache. If the NPU-written cache line
\nis still present in the CPU cache when the caller reads the buffer,
\nthe CPU observes stale data instead of the NPU response.<\/p>\n
This is a timing-sensitive bug: small mailbox buffers (~24 bytes)
\ntypically fit in a single cache line and may survive in the cache
\nuntil the caller reads them, producing silent data corruption rather
\nthan a crash. The bug is more likely to trigger when the caller reads
\nthe response immediately after dma_unmap_single() without intervening
\ncache-evicting operations.<\/p>\n
Fix by using DMA_BIDIRECTIONAL for both map and unmap, which ensures
\ndma_unmap_single() invalidates the CPU cache on non-coherent systems.
\nThe mailbox buffers are small so there is no performance concern.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net: airoha: Fix DMA direction for NPU mailbox buffer<\/p>\n
airoha_npu_send_msg() always maps the mailbox buffer with DMA_TO_DEVICE,
\nbut<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5428","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5428","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5428"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5428"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5428"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}