tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)
CVE-2026-99138 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-99138, released November 3, 2026. It is not reported as exploited. Patch Radar priority: High.
In the Linux kernel, the following vulnerability has been resolved: tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO) do_tcp_getsockopt() reads icsk->icsk_ca_ops and dereferences the get_info function pointer without rcu_read_lock(). With BPF struct_ops congestion control, ca_ops can point to dynamically allocated memory that is freed concurrently, resulting in a use-after-free when the kernel dereferences or calls through the stale pointer. BUG: KASAN: slab-use-after-free in do_tcp_getsockopt+0x2037/0x23e0 Read of size 8 at addr ffff888013701258 by task exploit/149 do_tcp_getsockopt+0x2037/0x23e0 (net/ipv4/tcp.c:4564) tcp_getsockopt+0x91/0xf0 __sys_getsockopt+0xf7/0x170 Fix this by wrapping the ca_ops load and get_info call within rcu_read_lock()/rcu_read_unlock(), and using READ_ONCE() to load the icsk_ca_ops pointer.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| linux · Debian 13.5 (trixie) | 6.12.115-2 | DEBIAN-CVE-2026-99138 | Nov 3, 2026 |
| linux · Debian 14 | 7.2.13-1 | DEBIAN-CVE-2026-99138 | Nov 3, 2026 |
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