Answer in brief
CVE-2026-90090 records a Unknown severity vulnerability in Bluetooth: btmtksdio: Fix out-of-bounds DMA read in the TX path. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=9aebfd4a2200ab8075e44379c758bccefdc589bb <c8742f53c9ef623decd5285403df0e5b5273c9fd || >=9aebfd4a2200ab8075e44379c758bccefdc589bb <0b71a6caaf284915c8cf9cd320ecee9f0361824a || >=9aebfd4a2200ab8075e44379c758bccefdc589bb <9a785ea864214aaffd8300683825c3f788d0b634 || >=9aebfd4a2200ab8075e44379c758bccefdc589bb <7b37556d7d801b79096c7ba8ea92db2338aa8b00 || >=9aebfd4a2200ab8075e44379c758bccefdc589bb <7b80d2701a68456c536f82e577dbed2f60ccb82b || >=9aebfd4a2200ab8075e44379c758bccefdc589bb <fa0ad2d277c7adead61d1c22411c55cea6990c2a | c8742f53c9ef623decd5285403df0e5b5273c9fd, 0b71a6caaf284915c8cf9cd320ecee9f0361824a, 9a785ea864214aaffd8300683825c3f788d0b634, 7b37556d7d801b79096c7ba8ea92db2338aa8b00, 7b80d2701a68456c536f82e577dbed2f60ccb82b, fa0ad2d277c7adead61d1c22411c55cea6990c2a |
| Linux/Linuxgeneric | 5.2 | Not reported |
Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 17, 2026
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btmtksdio: Fix out-of-bounds DMA read in the TX path btmtksdio_tx_packet() rounds the transfer size up to the SDIO block size of 256 bytes, but hands the host controller the SKB buffer as is: err = sdio_writesb(bdev->func, MTK_REG_CTDR, skb->data, round_up(skb->len, MTK_SDIO_BLOCK_SIZE)); Only skb->len bytes hold packet data, so the controller reads up to 255 bytes of uninitialised memory and sends it to the device over the SDIO bus. Depending on how much tailroom slack the SKB allocation happens to carry, that read can also extend past the end of the buffer. Compute the padded length up front, ensure the SKB has tailroom for it, and zero-fill the padding with skb_put_zero(). skb->len then covers the padding, so sdio_writesb() no longer needs to round up. byte_tx keeps counting the header and the payload only, and the error path restores the SKB so that the caller can requeue it. Writing behind skb->tail is only safe because the driver owns the buffer, which "Bluetooth: btmtksdio: Take exclusive ownership of the SKB before TX" ensures.
Quoted source text, attributed separately from HOL analysis.