CVE-2026-98300

In the Linux kernel, the following vulnerability has been resolved:

tcp: Don't call skb clone and charge r() for close()d listener in tcp v6 do rcv().

tcp v6 do rcv() no longer calls skb clone and charge r() for TCP LISTEN since commit 073d89808c06 ("net: fix data-races around sk->sk forward alloc").

However, there is still a small race window between tcp v6 rcv() and tcp v6 do rcv(), where concurrent close() changes TCP LISTEN to TCP CLOSE, causing skb clone and charge r() to be called locklessly and resulting in the splat below. [0]

Let's avoid calling skb clone and charge r() for TCP CLOSE as well.

This is fine for non-listeners because tcp rcv state process() drops skb for TCP CLOSE and opt skb was freed immediately anyway.

[0]: sk->sk forward alloc WARNING: net/ipv4/af inet.c:162 at inet sock destruct+0x64d/0x810 net/ipv4/af inet.c:162, CPU#1: ksoftirqd/1/28 Modules linked in: CPU: 1 UID: 0 PID: 28 Comm: ksoftirqd/1 Not tainted 7.2.0 #17 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 RIP: 0010:inet sock destruct+0x64d/0x810 net/ipv4/af inet.c:162 Code: 3d 49 ff e9 06 fd ff ff e8 d0 5b 83 f8 90 0f 0b 90 e9 35 fe ff ff e8 c2 5b 83 f8 90 0f 0b 90 e9 c5 fe ff ff e8 b4 5b 83 f8 90 <0f> 0b 90 e9 04 ff ff ff e8 a6 5b 83 f8 90 0f 0b 90 e9 65 fe ff ff RSP: 0018:ffffc90000677bb8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880117bde80 RCX: ffffffff8957eb41 RDX: ffff88801dad5d00 RSI: ffffffff8957ec3c RDI: 0000000000000005 RBP: 00000000fffff000 R08: ffffffff8957eb41 R09: 00000000fffff000 R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880117bdf10 R14: ffffffff81c08eb7 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880d7ae5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f93a1021138 CR3: 00000000207a9000 CR4: 0000000000350ef0 Call Trace: sk destruct+0x82/0xae0 net/core/sock.c:2356 rcu do batch kernel/rcu/tree.c:2645 [inline] rcu core+0x59c/0x1100 kernel/rcu/tree.c:2897 handle softirqs+0x1e4/0x9b0 kernel/softirq.c:622 run ksoftirqd kernel/softirq.c:1076 [inline] run ksoftirqd+0x38/0x60 kernel/softirq.c:1068 smpboot thread fn+0x458/0xc80 kernel/smpboot.c:160 kthread+0x396/0x4a0 kernel/kthread.c:436 ret from fork+0x8e0/0xe40 arch/x86/kernel/process.c:158 ret from fork asm+0x1a/0x30 arch/x86/entry/entry 64.S:245