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CVE-2026-90138— vsock: don't check the listener's sk_err in vsock_accept()

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，已修复以下漏洞： vsock：在 中不要检查监听套接字的 Syzbot 报告了一个可通过以下步骤复现的问题： 其基本原理是：创建了一个套接字（r0）并在绑定后触发自连接。由于该自连接回环到 r0，而 r0 当时仍处于 状态，导致其被错误地派发到客户端连接处理路径。在该路径中遇到的意外数据包类型将 设置为 。 随后，在同一个套接字上调用了 。由于内核的监听处理路径从不检查或清除 ，因此 调用成功。接着，创建了一个新的套接字（r1）作为普通客户端，并连接到 r0。然而， 拒绝了这个传入连接，因为

AI Predicted 5.5 Difficulty: Moderate EPSS 0.21% · P10

Possible ATT&CK Techniques 1 AI

T1505 · Server Software Component

Affected Version Matrix 10

VendorProduct Version RangeStatus
Linux Linux d021c344051af91f42c5ba9fdedc176740cbd238< c5a75d37c21e558cc6fad1597e732ead30745eed affected
d021c344051af91f42c5ba9fdedc176740cbd238< 36e5fa009f98a4edbe1783ac11c0df672b224742 affected
d021c344051af91f42c5ba9fdedc176740cbd238< 491b368a0c6e5f28b615a50b0d384f5c25fde2a7 affected
d021c344051af91f42c5ba9fdedc176740cbd238< b8c899cf5e7be29840a172c183dedd8d3e7a0287 affected
3.9 affected
< 3.9 unaffected
6.12.110≤ 6.12.* unaffected
6.18.52≤ 6.18.* unaffected
… +2 more rows
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I. Basic Information for CVE-2026-90138

Vulnerability Information
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Vulnerability Title
vsock: don't check the listener's sk_err in vsock_accept()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: vsock: don't check the listener's sk_err in vsock_accept() Syzbot reported an issue which can be reproduced with these steps: r0 = socket(AF_VSOCK, SOCK_STREAM, 0) bind(r0, {VMADDR_CID_ANY, PORT}) connect(r0, {VMADDR_CID_LOCAL, PORT}) -> -1, EPROTO (self-connect) listen(r0, backlog) -> 0 r1 = socket(AF_VSOCK, SOCK_STREAM, 0) connect(r1, {VMADDR_CID_LOCAL, PORT}) -> 0 accept(r0) -> -1, EPROTO (stale sk_err) Basically, it creates a socket (r0) and triggers a self-connect after binding it. This self-connect fails with EPROTO because it loops back to r0 while the socket is still in the TCP_SYN_SENT state, causing it to be incorrectly dispatched to the connecting-client path. The unexpected packet type encountered there sets sk_err to EPROTO. After that, it invokes a listen() call on the same socket. This listen() call succeeds because the kernel's listening path never inspects or clears sk_err. Then, a new socket (r1) is created as a normal client and connects to r0. However, vsock_accept() rejects this incoming connection because the listener's sk_err still holds the EPROTO error from the earlier failed self-connect. This rejection causes the child socket created for r1's connection to never be freed on virtio or hyperv transports; only the VMCI transport implements pending_work to revisit and clean up a rejected socket. For a non-blocking connect(), vsock_connect() may return -EINPROGRESS immediately, and vsock_connect_timeout() can later set sk->sk_err asynchronously. Since no vsock transport ever sets sk_err on a socket while it is in TCP_LISTEN state, checking it in vsock_accept() serves no purpose and only carries forward errors left behind by earlier, unrelated connection attempts on the same socket. Remove the checks so accept() no longer rejects valid incoming connections because of a stale error, which also avoids the resource leak described above.
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 d021c344051af91f42c5ba9fdedc176740cbd238 ~ c5a75d37c21e558cc6fad1597e732ead30745eed -
Linux Linux 3.9 -

II. Public POCs for CVE-2026-90138

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III. Intelligence Information for CVE-2026-90138

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Patches & Fixes for CVE-2026-90138 (4)

Same Patch Batch · Linux · 2026-09-17 · 600 CVEs total

CVE-2026-90235 9.8 CRITICAL sunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE
CVE-2026-90104 9.8 CRITICAL NFSv4.1: zero referring call lists before decoding
CVE-2026-92489 9.8 CRITICAL xfrm: Fix skb double-free in xfrm_dev_direct_output()
CVE-2026-90173 9.8 CRITICAL smb: smbdirect: free completion queues with ib_free_cq()
CVE-2026-90151 9.8 CRITICAL NFSv4: remove callback IDR entry on client allocation failure
CVE-2026-90110 9.4 CRITICAL inetpeer: randomize RB-tree node comparison using SipHash
CVE-2026-90230 9.1 CRITICAL nvmet: fix heap out-of-bounds read in nvmet_auth_negotiate()
CVE-2026-90414 9.1 CRITICAL IB/isert: reject PDUs declaring more data than was received
CVE-2026-90413 9.1 CRITICAL IB/isert: reject login PDUs declaring more data than was received
CVE-2026-93189 8.8 HIGH HID: core: quiesce input in hid_hw_stop() to prevent use-after-free
CVE-2026-90256 8.8 HIGH Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind
CVE-2026-93042 8.8 HIGH dmaengine: dw-edma: Terminate all descriptors without callbacks
CVE-2026-90286 8.8 HIGH drm/amdgpu/gfx6: Use PFP on the compute queues too
CVE-2026-90255 8.8 HIGH Bluetooth: hci_conn: fix the SCO setup context lifetime
CVE-2026-90425 8.8 HIGH iommu/tegra241-cmdqv: Require exactly one Stream ID for a vSID
CVE-2026-90329 8.8 HIGH HID: synchronize input before cleaning up a failed probe
CVE-2026-90162 8.8 HIGH ksmbd: defer publishing granted locks to prevent UAF/double-free race
CVE-2026-90240 8.8 HIGH iommu/vt-d: Flush context cache with correct SID when tearing down aliases
CVE-2026-90367 8.8 HIGH wifi: mt76: mt7996: hold dev->mt76.mutex while disabling tx worker in SER
CVE-2026-90371 8.8 HIGH wifi: mt76: fix RXDMAD_C buffer recycling race

Showing top 20 of 600 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-90138

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