Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix null-ptr-deref when acquiring remote ip of ethernet bearer
The reproduction steps:
- create a tun interface
- enable l2 bearer
- TIPC_NL_UDP_GET_REMOTEIP with media name set to tun
tipc: Started in network mode tipc: Node identity 8af312d38a21, cluster identity 4711 tipc: Enabled bearer eth:syz_tun, priority 1 Oops: general protection fault KASAN: null-ptr-deref in range CPU: 1 UID: 1000 PID: 559 Comm: poc Not tainted 6.16.0-rc1+ #117 PREEMPT Hardware name: QEMU Ubuntu 24.04 PC RIP: 0010:tipc_udp_nl_dump_remoteip+0x4a4/0x8f0
the ub was in fact a struct dev.
when bid != 0 && skip_cnt != 0, bearer_list[bid] may be NULL or other media when other thread changes it.
fix this by checking media_id.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 4.15.0 (+8 more)
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix null-ptr-deref when acquiring remote ip of ethernet bearer
The reproduction steps:
- create a tun interface
- enable l2 bearer
- TIPC_NL_UDP_GET_REMOTEIP with media name set to tun
tipc: Started in network mode tipc: Node identity 8af312d38a21, cluster identity 4711 tipc: Enabled bearer eth:syz_tun, priority 1 Oops: general protection fault KASAN: null-ptr-deref in range CPU: 1 UID: 1000 PID: 559 Comm: poc Not tainted 6.16.0-rc1+ #117 PREEMPT Hardware name: QEMU Ubuntu 24.04 PC RIP: 0010:tipc_udp_nl_dump_remoteip+0x4a4/0x8f0
the ub was in fact a struct dev.
when bid != 0 && skip_cnt != 0, bearer_list[bid] may be NULL or other media when other thread changes it.
fix this by checking media_id.