CVE-2026-74654
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dma: Clear stale RX state on shutdown serial8250_release_dma() terminates RX DMA and releases the channel, but leaves rx_running set. If the port is closed while an RX transfer is active, the stale state remains while rxchan is NULL until the channel is requested again on the next open. The DesignWare BUSY workaround added by commit a7b9ce39fbe4 ("serial: 8250_dw: Ensure BUSY is deasserted") calls serial8250_rx_dma_flush() from the LCR write path during startup. This happens before serial8250_request_dma() obtains a new RX channel. On reopen, the stale rx_running state therefore makes the flush path pass a NULL channel to dmaengine_pause(), causing a kernel Oops. Clear rx_running after terminating RX DMA, matching the TX cleanup. Also make the flush helper return if the DMA object or RX channel is not available so startup and teardown paths cannot pass a NULL channel to the DMAengine API.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-22 16:16:38.937000
Last modified
2026-11-06 17:19:52.583000
View original CVE JSON
{
"id": "CVE-2026-74654",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-22T16:16:38.937",
"lastModified": "2026-11-06T17:19:52.583",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nserial: 8250_dma: Clear stale RX state on shutdown\n\nserial8250_release_dma() terminates RX DMA and releases the channel, but\nleaves rx_running set. If the port is closed while an RX transfer is\nactive, the stale state remains while rxchan is NULL until the channel is\nrequested again on the next open.\n\nThe DesignWare BUSY workaround added by commit a7b9ce39fbe4\n(\"serial: 8250_dw: Ensure BUSY is deasserted\") calls\nserial8250_rx_dma_flush() from the LCR write path during startup. This\nhappens before serial8250_request_dma() obtains a new RX channel. On\nreopen, the stale rx_running state therefore makes the flush path pass a\nNULL channel to dmaengine_pause(), causing a kernel Oops.\n\nClear rx_running after terminating RX DMA, matching the TX cleanup. Also\nmake the flush helper return if the DMA object or RX channel is not\navailable so startup and teardown paths cannot pass a NULL channel to the\nDMAengine API."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nserial: 8250_dma: Borrar estado RX obsoleto al apagarse\n\nserial8250_release_dma() termina el DMA RX y libera el canal, pero deja rx_running establecido. Si el puerto se cierra mientras una transferencia RX está activa, el estado obsoleto permanece mientras rxchan es NULL hasta que el canal es solicitado de nuevo en la siguiente apertura.\n\nLa solución alternativa DesignWare BUSY añadida por el commit a7b9ce39fbe4 ('serial: 8250_dw: Ensure BUSY is deasserted') llama a serial8250_rx_dma_flush() desde la ruta de escritura LCR durante el inicio. Esto ocurre antes de que serial8250_request_dma() obtenga un nuevo canal RX. Al reabrir, el estado rx_running obsoleto, por lo tanto, hace que la ruta de vaciado pase un canal NULL a dmaengine_pause(), causando un Oops del kernel.\n\nBorrar rx_running después de terminar el DMA RX, coincidiendo con la limpieza TX. También hacer que la función auxiliar de vaciado retorne si el objeto DMA o el canal RX no está disponible para que las rutas de inicio y de desmontaje no puedan pasar un canal NULL a la API de DMAengine."
}
],
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{
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"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
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],
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{
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},
{
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"lessThanOrEqual": "6.18.*",
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},
{
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}
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"metrics": {
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{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T17:00:25.809181Z",
"id": "CVE-2026-74654",
"options": [
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},
{
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],
"role": "CISA Coordinator",
"version": "2.0.3"
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