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CVE-2026-99139— tcp: fix use-after-free in do_tcp_getsockopt(TCP_CONGESTION)

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Linux 内核中，以下漏洞已被修复： tcp: 修复 do_tcp_getsockopt(TCP_CONGESTION) 中的释放后使用（use-after-free）问题 函数在读取 时未持有 。自提交 0baf26b0fcd7（"bpf: tcp: 支持在 bpf 中使用 tcp_congestion_ops"）之后， 可能指向动态分配的 BPF 内存，而该内存可能通过 被并发释放，从而导致释放后使用（use-after-free）漏洞。 触发场景示例： 修复方案： 通过在访问 期间持有 ，使用 加载 ，

AI Predicted 7.8 Difficulty: Hard
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I. Basic Information for CVE-2026-99139

Vulnerability Information
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Vulnerability Title
tcp: fix use-after-free in do_tcp_getsockopt(TCP_CONGESTION)
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: tcp: fix use-after-free in do_tcp_getsockopt(TCP_CONGESTION) do_tcp_getsockopt() reads icsk->icsk_ca_ops->name without holding rcu_read_lock(). Since commit 0baf26b0fcd7 ("bpf: tcp: Support tcp_congestion_ops in bpf"), icsk_ca_ops can point to dynamically allocated BPF struct_ops memory that may be freed concurrently via setsockopt(TCP_CONGESTION), leading to a use-after-free. BUG: KASAN: slab-use-after-free in _copy_to_user+0x37/0x60 Read of size 16 at addr ffff888013505260 by task exploit/149 _copy_to_user+0x37/0x60 do_tcp_getsockopt+0x158a/0x2460 (net/ipv4/tcp.c:4585) tcp_getsockopt+0x91/0xf0 __sys_getsockopt+0xf7/0x170 Fix this by holding rcu_read_lock() around the ca_ops->name access, using READ_ONCE() to load icsk_ca_ops, and copying the name to a stack buffer before releasing the lock. Also annotate the relevant icsk_ca_ops stores with WRITE_ONCE() to fix the accompanying KCSAN data-race issue.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 0baf26b0fcd74bbfcef53c5d5e8bad2b99c8d0d2 ~ c1804ef016392dd91267d2207ee43b1de34302ca -
Linux Linux 5.6 -

II. Public POCs for CVE-2026-99139

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III. Intelligence Information for CVE-2026-99139

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Patches & Fixes for CVE-2026-99139 (3)

Same Patch Batch · Linux · 2026-10-28 · 117 CVEs total

CVE-2026-99144 sched_ext: Fix use-after-free of a destroyed user DSQ by a deferred reenqueue
CVE-2026-99129 selinux: fix BPF token permission checks
CVE-2026-99130 io_uring/cancel: don't spin on local work the task can't run
CVE-2026-99131 xfs: fix capability check in xfs
CVE-2026-99133 net/iucv: fix the recvmsg window update
CVE-2026-99132 xfs: don't hold buffer locks across sync transaction commit in xfs_sync_sb_buf
CVE-2026-99134 mac802154: fix data race and NULL deref on local->assoc_dev
CVE-2026-99135 dm-integrity: fix infinite loop on discard with large tag size
CVE-2026-99137 cifs: don't update i_size in cifs_do_truncate without a cached handle
CVE-2026-99136 dm-crypt: fix a tiny race condition in crypt_dec_pending
CVE-2026-99138 tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)
CVE-2026-99140 tracing: Fix hist trigger timestamps for buffered events
CVE-2026-99141 tracing: Fix crash in print_graph_function_event()
CVE-2026-99142 tracing: Check operator stack capacity before pushing
CVE-2026-99143 tracing: Keep the predicate limit separate from program capacity
CVE-2026-99156 scsi: st: Fix use-after-free race between st_remove() and st_open()
CVE-2026-99153 scsi: libiscsi: Validate the ITT reflected in a Reject PDU
CVE-2026-99152 scsi: libiscsi: Validate the task named by a management response
CVE-2026-99154 scsi: libiscsi: Reject a negative task index from parse_pdu_itt
CVE-2026-99151 drm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions

Showing top 20 of 117 CVEs. View all on vendor page → →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux