Race in Linux kernel TCP IPv6 receive path after close()
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 6 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 4.4 has a race in the TCP IPv6 receive path. A concurrent close() changes a listening socket to closed while tcp_v6_do_rcv() handles a packet, so skb_clone_and_charge_r() runs without the lock and triggers a kernel warning when the socket is destroyed.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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: <TASK> __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 </TASK>
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
The Linux kernel fixed versions are 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8 and 7.3. Red Hat lists no fix planned for Red Hat Enterprise Linux 6 and no fix available for Red Hat Enterprise Linux 8, 9 and 10 and Red Hat OpenShift Container Platform 4 and 5.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-06 Threatist record created from CVE-2026-98300
- 2026-10-06 Alias added: GHSA-jr77-63hq-vhgr
- 2026-10-11 Affected versions changed · Red Hat
- 2026-10-11 CVSS score added · Red Hat
- 2026-10-16 CVSS score changed · Red Hat
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/a23a3bc5004df6434de05797e0b6b2ecf864b86a
- https://git.kernel.org/stable/c/1cb7f292a337fdc72a8219bcd9d40a9cf5e86db5
- https://git.kernel.org/stable/c/7d94602e77a4525611afebb23149145ac242afd7
- https://git.kernel.org/stable/c/b727e3d58cb906f1506c1334dfba71fbb1338339
- https://git.kernel.org/stable/c/3e3394a13b603cc79b6a35480b8e20df6c716944
- https://git.kernel.org/stable/c/619bfbaacbff6a9822923f69f6af29d7f66a870c
- https://git.kernel.org/stable/c/56d38839ef0bff6526d9bd73b6811bd00316b21c
- https://git.kernel.org/stable/c/8e759cd1f6444a946bd1fd2b2b29eea582eea1d5
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Sources
- CVE-2026-98300 · CVE Program
- CVE-2026-98300 · NVD
- FIRST EPSS
- GHSA-jr77-63hq-vhgr · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98300 · Red Hat security data · CC BY 4.0
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