Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net/af_iucv: fix NULL deref in afiucv_hs_callback_syn()
afiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC. If the allocation fails, nsk is NULL.
The connection-refused path is entered when the listen state check fails, the accept backlog is full, or nsk is NULL. The code unconditionally calls iucv_sock_kill(nsk) in that path.
iucv_sock_kill() does not accept a NULL socket pointer and immediately dereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL, calling iucv_sock_kill(nsk) results in a NULL pointer dereference.
Only call iucv_sock_kill() when a child socket was successfully allocated.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 4.19.0 (+17 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Will Not Fix |
43 kernels
|
| Debian 13 | Will Not Fix |
14 kernels
|
| Ubuntu 22.04 | Planned | — |
| Ubuntu 22.04 AWS | Planned | — |
| Ubuntu 22.04 Azure | Planned | — |
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |
| Ubuntu 26.04 | Will Not Fix |
2 kernels
|