Description
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE
__hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a
single tx_buf of MAX_TX_BUF_SIZE (32768) bytes, limiting the batch
by record count but never by cumulative byte length.
With large frames (MTU 2304), 20 aggregated frames of 2292 bytes
each exceed the allocation (20 * 2296 = 45920 bytes), so the
memcpy() in the loop writes up to 13152 bytes past tx_buf->buf
before usb_submit_urb().
Peek the queue head and stop before copying any record that would
cross MAX_TX_BUF_SIZE, then dispatch the current batch. Leftover
skbs remain queued and are drained on the next URB completion.
The byte bound changes the loop's exit semantics: it can now exit
before i == tx_skb_cnt - 1. Stock only finalized tx_buf->len on
that last index (len += offset), so an early break would submit a
URB holding only the last record's length while every dequeued skb
is freed on completion, silently dropping frames. Make tx_buf->len
a running total and advance tx_buf->offset per record instead; the
stride round_up(nskb->len + 4, 4) is identical to the stock stride
when the loop runs to completion.
Tested on hardware with an MTU 2304 flood: the loop stops at
record 15 (len = 32144, offset = 32144, within 32768), no
oversized URB is submitted, and MTU 1500 pings pass 20/20.
wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE
__hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a
single tx_buf of MAX_TX_BUF_SIZE (32768) bytes, limiting the batch
by record count but never by cumulative byte length.
With large frames (MTU 2304), 20 aggregated frames of 2292 bytes
each exceed the allocation (20 * 2296 = 45920 bytes), so the
memcpy() in the loop writes up to 13152 bytes past tx_buf->buf
before usb_submit_urb().
Peek the queue head and stop before copying any record that would
cross MAX_TX_BUF_SIZE, then dispatch the current batch. Leftover
skbs remain queued and are drained on the next URB completion.
The byte bound changes the loop's exit semantics: it can now exit
before i == tx_skb_cnt - 1. Stock only finalized tx_buf->len on
that last index (len += offset), so an early break would submit a
URB holding only the last record's length while every dequeued skb
is freed on completion, silently dropping frames. Make tx_buf->len
a running total and advance tx_buf->offset per record instead; the
stride round_up(nskb->len + 4, 4) is identical to the stock stride
when the loop runs to completion.
Tested on hardware with an MTU 2304 flood: the loop stops at
record 15 (len = 32144, offset = 32144, within 32768), no
oversized URB is submitted, and MTU 1500 pings pass 20/20.
Published:
2026-10-18
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
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 |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Sun, 18 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE __hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a single tx_buf of MAX_TX_BUF_SIZE (32768) bytes, limiting the batch by record count but never by cumulative byte length. With large frames (MTU 2304), 20 aggregated frames of 2292 bytes each exceed the allocation (20 * 2296 = 45920 bytes), so the memcpy() in the loop writes up to 13152 bytes past tx_buf->buf before usb_submit_urb(). Peek the queue head and stop before copying any record that would cross MAX_TX_BUF_SIZE, then dispatch the current batch. Leftover skbs remain queued and are drained on the next URB completion. The byte bound changes the loop's exit semantics: it can now exit before i == tx_skb_cnt - 1. Stock only finalized tx_buf->len on that last index (len += offset), so an early break would submit a URB holding only the last record's length while every dequeued skb is freed on completion, silently dropping frames. Make tx_buf->len a running total and advance tx_buf->offset per record instead; the stride round_up(nskb->len + 4, 4) is identical to the stock stride when the loop runs to completion. Tested on hardware with an MTU 2304 flood: the loop stops at record 15 (len = 32144, offset = 32144, within 32768), no oversized URB is submitted, and MTU 1500 pings pass 20/20. | |
| Title | wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:49:20.872Z
Reserved: 2026-09-25T10:25:14.372Z
Link: CVE-2026-98827
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:17:36.937
Modified: 2026-10-18T16:17:36.937
Link: CVE-2026-98827
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.