i3c: master: svc: bound IBI payload to the requested max_payload_len
Summary
| CVE | CVE-2026-80951 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-11 20:19:00 UTC |
| Updated | 2026-09-14 13:18:50 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: i3c: master: svc: bound IBI payload to the requested max_payload_len svc_i3c_master_handle_ibi() reads the IBI payload from the RX FIFO into the IBI slot. The loop is bounded by the hardware FIFO size (SVC_I3C_FIFO_SIZE), not by the slot size. slot->data points into the IBI pool, which i3c_generic_ibi_alloc_pool() sizes at max_payload_len per slot. svc_i3c_master_request_ibi() only rejects a max_payload_len larger than SVC_I3C_FIFO_SIZE, so a driver can request a smaller one. mctp-i3c requests 1. Each readsb() then copies the controller RXCOUNT bytes (up to 31) with no check against the slot size. A device that sends more bytes than the slot holds writes past slot->data, an out-of-bounds write into the IBI pool. Bound the loop by dev->ibi->max_payload_len and clamp each read to the space left in the slot, the same way dw-i3c does. A device can still send more than the requested payload. Flush the leftover bytes from the RX FIFO so they do not leak into the next transfer. |
Risk And Classification
EPSS: 0.002000000 probability, percentile 0.099550000 (date 2026-09-14)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected dd3c52846d5954acd43f0e771689302f27dadc28 7c099b0b292a68d0ef558527945dbfb756fbf893 git | Not specified |
| CNA | Linux | Linux | affected dd3c52846d5954acd43f0e771689302f27dadc28 7cc5ba756bc1cfffab9cb2695742f9f479dc73f7 git | Not specified |
| CNA | Linux | Linux | affected dd3c52846d5954acd43f0e771689302f27dadc28 35aa6730b8c5626b879a4e893fe664f59bf07d7f git | Not specified |
| CNA | Linux | Linux | affected dd3c52846d5954acd43f0e771689302f27dadc28 f296a0d5907bf88314dfda67245f7f69d1552470 git | Not specified |
| CNA | Linux | Linux | affected dd3c52846d5954acd43f0e771689302f27dadc28 5697d779577e2786ff3348ae9b77020ac0cf0aab git | Not specified |
| CNA | Linux | Linux | affected dd3c52846d5954acd43f0e771689302f27dadc28 aac3c5aababc7fb69d5bf5b0cc52d308574e3a8c git | Not specified |
| CNA | Linux | Linux | affected dd3c52846d5954acd43f0e771689302f27dadc28 e2bda39d7f9f285ec803e200b5c1f17143d0b483 git | Not specified |
| CNA | Linux | Linux | affected 5.12 | Not specified |
| CNA | Linux | Linux | unaffected 5.12 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.221 5.15.* 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 6.12.109 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.50 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.4 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/7c099b0b292a68d0ef558527945dbfb756fbf893 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/aac3c5aababc7fb69d5bf5b0cc52d308574e3a8c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7cc5ba756bc1cfffab9cb2695742f9f479dc73f7 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/35aa6730b8c5626b879a4e893fe664f59bf07d7f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/f296a0d5907bf88314dfda67245f7f69d1552470 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5697d779577e2786ff3348ae9b77020ac0cf0aab | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e2bda39d7f9f285ec803e200b5c1f17143d0b483 | 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.