vhost-vdpa: don't install the eventfd_ctx_fdget() error in config_ctx
Summary
| CVE | CVE-2026-97993 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:27 UTC |
| Updated | 2026-09-25 11:17:27 UTC |
| 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. |
Risk And Classification
EPSS: 0.002000000 probability, percentile 0.088250000 (date 2026-09-27)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 776f395004d829bbbf18c159ed9beb517a208c71 388c678639a0cebfd936b3e56c64ac6a371efec2 git | Not specified |
| CNA | Linux | Linux | affected 776f395004d829bbbf18c159ed9beb517a208c71 65faf9eaa00e408e1406fbcf675c8c8d0e27ff2a git | Not specified |
| CNA | Linux | Linux | affected 776f395004d829bbbf18c159ed9beb517a208c71 6b20b40f020bde236f6b8a08ff88d8653261ec2b git | Not specified |
| CNA | Linux | Linux | affected 776f395004d829bbbf18c159ed9beb517a208c71 e74a9fa50749b9940b4fb13199652325e08d3c4a git | Not specified |
| CNA | Linux | Linux | affected 5.8 | Not specified |
| CNA | Linux | Linux | unaffected 5.8 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.111 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.53 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/65faf9eaa00e408e1406fbcf675c8c8d0e27ff2a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e74a9fa50749b9940b4fb13199652325e08d3c4a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/6b20b40f020bde236f6b8a08ff88d8653261ec2b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/388c678639a0cebfd936b3e56c64ac6a371efec2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.