ppp_synctty: ensure a writeable skb header
Summary
| CVE | CVE-2026-97964 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:24 UTC |
| Updated | 2026-10-19 10:17:47 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: ppp_synctty: ensure a writeable skb header ppp_sync_txmunge() checks headroom before prepending the address and control bytes, but does not ensure that the skb header is writable. A received skb can reach this function through PPP channel bridging without passing through ppp_start_xmit(), which calls skb_cow_head(). For example, a PPPoE frame may share its buffer with a clone queued to an AF_PACKET socket. If it is bridged to a synchronous tty channel, the address/control bytes can overwrite data still visible to that socket. Use skb_cow_head() to ensure both sufficient headroom and a writable header. |
Risk And Classification
EPSS: 0.001720000 probability, percentile 0.059970000 (date 2026-10-05)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 4cf476ced45d7f12df30a68e833b263e7a2202d1 25e03eeead2c49748c7582dfb64c205f93a42d00 git | Not specified |
| CNA | Linux | Linux | affected 4cf476ced45d7f12df30a68e833b263e7a2202d1 a256f9925288ef47de8febed5c38d5cc21340211 git | Not specified |
| CNA | Linux | Linux | affected 4cf476ced45d7f12df30a68e833b263e7a2202d1 7953946f68262a8bb137aa101249adef6e029652 git | Not specified |
| CNA | Linux | Linux | affected 4cf476ced45d7f12df30a68e833b263e7a2202d1 3af7797fbabc84992e0ca5ad2bc0ca8537d053ef git | Not specified |
| CNA | Linux | Linux | affected 4cf476ced45d7f12df30a68e833b263e7a2202d1 0996c3e6bcc6ae08cb371ed43648c9f7f748ae6e git | Not specified |
| CNA | Linux | Linux | affected 4cf476ced45d7f12df30a68e833b263e7a2202d1 15d0a6c9a42df2d745c37510dba828f6dbe60d9f git | Not specified |
| CNA | Linux | Linux | affected 4cf476ced45d7f12df30a68e833b263e7a2202d1 8aaeb56aff2a557a88f83ae866da2c91ad247e59 git | Not specified |
| CNA | Linux | Linux | affected 5.11 | Not specified |
| CNA | Linux | Linux | unaffected 5.11 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.222 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.189 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.158 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.111 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.53 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/a256f9925288ef47de8febed5c38d5cc21340211 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/15d0a6c9a42df2d745c37510dba828f6dbe60d9f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/7953946f68262a8bb137aa101249adef6e029652 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/25e03eeead2c49748c7582dfb64c205f93a42d00 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/8aaeb56aff2a557a88f83ae866da2c91ad247e59 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0996c3e6bcc6ae08cb371ed43648c9f7f748ae6e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/3af7797fbabc84992e0ca5ad2bc0ca8537d053ef | 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.