{"id":"CVE-2026-98827","title":"wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE\n\n__hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a\nsingle tx_buf of MAX_TX_BUF_SIZE (32768) byte…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < c18882768a0fe253c70986c5fe66d9241570fbc4","Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < 345ce265cf604e84b5b560c21beaf4c6f269ab14","Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < e73a619f91b6cfec47bc1a94aea28df6849e5be3","Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < aeaca27c1db3106967ffbb2b517d98c835f6d500","Linux 2.6.35"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:49:20.872Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98827","references":[{"url":"https://git.kernel.org/stable/c/c18882768a0fe253c70986c5fe66d9241570fbc4"},{"url":"https://git.kernel.org/stable/c/345ce265cf604e84b5b560c21beaf4c6f269ab14"},{"url":"https://git.kernel.org/stable/c/e73a619f91b6cfec47bc1a94aea28df6849e5be3"},{"url":"https://git.kernel.org/stable/c/aeaca27c1db3106967ffbb2b517d98c835f6d500"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.472Z","slug":"CVE-2026-98827","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE\n\n__hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a\nsingle tx_buf of MAX_TX_BUF_SIZE (32768) bytes, limiting the batch\nby record count but never by cumulative byte length.\n\nWith large frames (MTU 2304), 20 aggregated frames of 2292 bytes\neach exceed the allocation (20 * 2296 = 45920 bytes), so the\nmemcpy() in the loop writes up to 13152 bytes past tx_buf->buf\nbefore usb_submit_urb().\n\nPeek the queue head and stop before copying any record that would\ncross MAX_TX_BUF_SIZE, then dispatch the current batch. Leftover\nskbs remain queued and are drained on the next URB completion.\n\nThe byte bound changes the loop's exit semantics: it can now exit\nbefore i == tx_skb_cnt - 1. Stock only finalized tx_buf->len on\nthat last index (len += offset), so an early break would submit a\nURB holding only the last record's length while every dequeued skb\nis freed on completion, silently dropping frames. Make tx_buf->len\na running total and advance tx_buf->offset per record instead; the\nstride round_up(nskb->len + 4, 4) is identical to the stock stride\nwhen the loop runs to completion.\n\nTested on hardware with an MTU 2304 flood: the loop stops at\nrecord 15 (len = 32144, offset = 32144, within 32768), no\noversized URB is submitted, and MTU 1500 pings pass 20/20.\n\n## Affected\n\n- `Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < c18882768a0fe253c70986c5fe66d9241570fbc4`\n- `Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < 345ce265cf604e84b5b560c21beaf4c6f269ab14`\n- `Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < e73a619f91b6cfec47bc1a94aea28df6849e5be3`\n- `Linux >= fb9987d0f748c983bb795a86f47522313f701a08 < aeaca27c1db3106967ffbb2b517d98c835f6d500`\n- `Linux 2.6.35`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}