{"id":"CVE-2026-98827","state":"PUBLISHED","title":"wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE","description":"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) 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.","publishedAt":"2026-10-18T15:49:20.872Z","updatedAt":"2026-10-19T09:26:19.987Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"c18882768a0fe253c70986c5fe66d9241570fbc4","versionType":"git"},{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"345ce265cf604e84b5b560c21beaf4c6f269ab14","versionType":"git"},{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"e73a619f91b6cfec47bc1a94aea28df6849e5be3","versionType":"git"},{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"aeaca27c1db3106967ffbb2b517d98c835f6d500","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath9k/hif_usb.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath9k/hif_usb.c"]}],"references":["https://git.kernel.org/stable/c/c18882768a0fe253c70986c5fe66d9241570fbc4","https://git.kernel.org/stable/c/345ce265cf604e84b5b560c21beaf4c6f269ab14","https://git.kernel.org/stable/c/e73a619f91b6cfec47bc1a94aea28df6849e5be3","https://git.kernel.org/stable/c/aeaca27c1db3106967ffbb2b517d98c835f6d500"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98827.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98827","state":"PUBLISHED","datePublished":"2026-10-18T15:49:20.872Z","dateUpdated":"2026-10-19T09:26:19.987Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.372Z"},"containers":{"cna":{"title":"wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE","descriptions":[{"lang":"en","value":"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) 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"c18882768a0fe253c70986c5fe66d9241570fbc4","versionType":"git"},{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"345ce265cf604e84b5b560c21beaf4c6f269ab14","versionType":"git"},{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"e73a619f91b6cfec47bc1a94aea28df6849e5be3","versionType":"git"},{"version":"fb9987d0f748c983bb795a86f47522313f701a08","status":"affected","lessThan":"aeaca27c1db3106967ffbb2b517d98c835f6d500","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath9k/hif_usb.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/ath/ath9k/hif_usb.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:26:19.987Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}