DocumentationOverview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , TuxCare 9.6 ESU , TuxCare 9.8 ESU
- Affected packages:
- kernel @ 5.14.0 (+2 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 9.2 ESU | In Rollout |
36 kernels
|
| Debian 12 | Planned | — |
| Debian 13 | Released |
17 kernels
|
| Oracle Linux 8 UEK 7 | Ready For Release | — |
| Oracle Linux 9 UEK 7 | Ready For Release | — |