Bluetooth: btmtksdio: Fix out-of-bounds DMA read in the TX path
Summary
| CVE | CVE-2026-90090 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-09-17 17:17:00 UTC |
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| Updated | 2026-09-17 17:17:00 UTC |
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| Description | 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. |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 9aebfd4a2200ab8075e44379c758bccefdc589bb c8742f53c9ef623decd5285403df0e5b5273c9fd git |
Not specified |
| CNA |
Linux |
Linux |
affected 9aebfd4a2200ab8075e44379c758bccefdc589bb 0b71a6caaf284915c8cf9cd320ecee9f0361824a git |
Not specified |
| CNA |
Linux |
Linux |
affected 9aebfd4a2200ab8075e44379c758bccefdc589bb 9a785ea864214aaffd8300683825c3f788d0b634 git |
Not specified |
| CNA |
Linux |
Linux |
affected 9aebfd4a2200ab8075e44379c758bccefdc589bb 7b37556d7d801b79096c7ba8ea92db2338aa8b00 git |
Not specified |
| CNA |
Linux |
Linux |
affected 9aebfd4a2200ab8075e44379c758bccefdc589bb 7b80d2701a68456c536f82e577dbed2f60ccb82b git |
Not specified |
| CNA |
Linux |
Linux |
affected 9aebfd4a2200ab8075e44379c758bccefdc589bb fa0ad2d277c7adead61d1c22411c55cea6990c2a git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.2 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.2 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.188 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.157 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.110 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.52 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.6 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/0b71a6caaf284915c8cf9cd320ecee9f0361824a |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/9a785ea864214aaffd8300683825c3f788d0b634 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/7b80d2701a68456c536f82e577dbed2f60ccb82b |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/7b37556d7d801b79096c7ba8ea92db2338aa8b00 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/fa0ad2d277c7adead61d1c22411c55cea6990c2a |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c8742f53c9ef623decd5285403df0e5b5273c9fd |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.