In the Linux kernel, the following vulnerability has been resolved:
serial: qcom-geni: do not advance stale DMA completions
The qcom GENI serial DMA TX completion path advances the transmit fifo by
the number of bytes recorded in port->tx_remaining.
If uart_flush_buffer() runs after the hardware has completed a DMA
transfer but before the DMA completion interrupt has been handled, the
serial core resets the transmit fifo while port->tx_remaining still
describes the old DMA transfer.
A previous fix avoided advancing an empty fifo by checking that the fifo
length is at least tx_remaining. That still does not distinguish the old
DMA payload from new bytes written after the flush. If userspace writes
new data before the stale DMA completion interrupt is handled, the fifo
can again contain at least tx_remaining bytes and the stale completion
can advance and discard those new bytes.
Mark an in-flight DMA transfer stale when the transmit fifo is flushed.
The later completion still unprepares the original DMA mapping using the
saved length, but it no longer advances the transmit fifo.
serial: qcom-geni: do not advance stale DMA completions
The qcom GENI serial DMA TX completion path advances the transmit fifo by
the number of bytes recorded in port->tx_remaining.
If uart_flush_buffer() runs after the hardware has completed a DMA
transfer but before the DMA completion interrupt has been handled, the
serial core resets the transmit fifo while port->tx_remaining still
describes the old DMA transfer.
A previous fix avoided advancing an empty fifo by checking that the fifo
length is at least tx_remaining. That still does not distinguish the old
DMA payload from new bytes written after the flush. If userspace writes
new data before the stale DMA completion interrupt is handled, the fifo
can again contain at least tx_remaining bytes and the stale completion
can advance and discard those new bytes.
Mark an in-flight DMA transfer stale when the transmit fifo is flushed.
The later completion still unprepares the original DMA mapping using the
saved length, but it no longer advances the transmit fifo.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||
| Linux | Linux | affected |
|
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: serial: qcom-geni: do not advance stale DMA completions The qcom GENI serial DMA TX completion path advances the transmit fifo by the number of bytes recorded in port->tx_remaining. If uart_flush_buffer() runs after the hardware has completed a DMA transfer but before the DMA completion interrupt has been handled, the serial core resets the transmit fifo while port->tx_remaining still describes the old DMA transfer. A previous fix avoided advancing an empty fifo by checking that the fifo length is at least tx_remaining. That still does not distinguish the old DMA payload from new bytes written after the flush. If userspace writes new data before the stale DMA completion interrupt is handled, the fifo can again contain at least tx_remaining bytes and the stale completion can advance and discard those new bytes. Mark an in-flight DMA transfer stale when the transmit fifo is flushed. The later completion still unprepares the original DMA mapping using the saved length, but it no longer advances the transmit fifo. | |
| Title | serial: qcom-geni: do not advance stale DMA completions | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:11:28.552Z
Reserved: 2026-09-17T16:02:15.086Z
Link: CVE-2026-93123
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:18:07.020
Modified: 2026-09-17T17:18:07.020
Link: CVE-2026-93123
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.