vhost-vdpa: don't install the eventfd_ctx_fdget() error in config_ctx

Description

In the Linux kernel, the following vulnerability has been resolved: vhost-vdpa: don't install the eventfd_ctx_fdget() error in config_ctx vhost_vdpa_set_config_call() swaps the eventfd_ctx_fdget() return value into v->config_ctx before checking it, so on failure the field briefly holds an ERR_PTR: ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd); swap(ctx, v->config_ctx); if (!IS_ERR_OR_NULL(ctx)) eventfd_ctx_put(ctx); if (IS_ERR(v->config_ctx)) { long ret = PTR_ERR(v->config_ctx); v->config_ctx = NULL; return ret; } Commit 0bde59c1723a ("vhost-vdpa: set v->config_ctx to NULL if eventfd_ctx_fdget() fails") added that clearing, and spelled out the invariant the rest of the file relies on: "we consider 'v->config_ctx' valid if it is not NULL". The window between the swap and the clearing still breaks it. vhost_vdpa_config_cb() only tests for NULL, so a config interrupt delivered inside the window hands the ERR_PTR to eventfd_signal(). Check the fd before installing it instead. That closes the window and matches how vhost_vring_ioctl() handles the same failure for the vq call fd. It also stops a rejected fd from tearing down a config interrupt that was working: until now the swap replaced the live context and put it, so after an EBADF the device silently stopped delivering config interrupts until userspace installed a new fd.

Timeline

Scores

No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.

EPSS (exploitation in 30 days)

0.22% · top 88% of all CVEs (12 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.

Affected products

• Linux · Linux

  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < e260dc9fbfdae0978e7a8698f977fbb463a657be
  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < 66e73fa18910b39fea0941dea5fe091122240855
  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < 4fde085eb839fbb39c25cbba5d2a091ded394877
  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < 59fc7c1c6b4d325194ca45352180340092d95098
  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < 388c678639a0cebfd936b3e56c64ac6a371efec2
  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < 65faf9eaa00e408e1406fbcf675c8c8d0e27ff2a
  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < 6b20b40f020bde236f6b8a08ff88d8653261ec2b
  • affected 776f395004d829bbbf18c159ed9beb517a208c71 – < e74a9fa50749b9940b4fb13199652325e08d3c4a

• Linux · Linux

  • affected 5.8
  • unaffected < 5.8
  • unaffected 5.10.271 – ≤ 5.10.*
  • unaffected 5.15.222 – ≤ 5.15.*
  • unaffected 6.1.189 – ≤ 6.1.*
  • unaffected 6.6.158 – ≤ 6.6.*
  • unaffected 6.12.111 – ≤ 6.12.*
  • unaffected 6.18.53 – ≤ 6.18.*
  • unaffected 7.2.7 – ≤ 7.2.*
  • unaffected 7.3 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-86647 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-97993](https://cveledger.app/badge/CVE-2026-97993.svg)](https://cveledger.app/cve/CVE-2026-97993)

Record last updated 19 Oct 2026, 09:12 UTC.