CVE-2026-97993
Full vulnerability record from the local CVENow database.
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.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-25 11:17:27.500000
Last modified
2026-10-19 10:17:50.730000
View original CVE JSON
{
"id": "CVE-2026-97993",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-25T11:17:27.500",
"lastModified": "2026-10-19T10:17:50.730",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost-vdpa: don't install the eventfd_ctx_fdget() error in config_ctx\n\nvhost_vdpa_set_config_call() swaps the eventfd_ctx_fdget() return value\ninto v->config_ctx before checking it, so on failure the field briefly\nholds an ERR_PTR:\n\n\tctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);\n\tswap(ctx, v->config_ctx);\n\n\tif (!IS_ERR_OR_NULL(ctx))\n\t\teventfd_ctx_put(ctx);\n\n\tif (IS_ERR(v->config_ctx)) {\n\t\tlong ret = PTR_ERR(v->config_ctx);\n\n\t\tv->config_ctx = NULL;\n\t\treturn ret;\n\t}\n\nCommit 0bde59c1723a (\"vhost-vdpa: set v->config_ctx to NULL if\neventfd_ctx_fdget() fails\") added that clearing, and spelled out the\ninvariant the rest of the file relies on: \"we consider 'v->config_ctx'\nvalid if it is not NULL\". The window between the swap and the clearing\nstill breaks it. vhost_vdpa_config_cb() only tests for NULL, so a config\ninterrupt delivered inside the window hands the ERR_PTR to\neventfd_signal().\n\nCheck the fd before installing it instead. That closes the window and\nmatches how vhost_vring_ioctl() handles the same failure for the vq call\nfd.\n\nIt also stops a rejected fd from tearing down a config interrupt that was\nworking: until now the swap replaced the live context and put it, so\nafter an EBADF the device silently stopped delivering config interrupts\nuntil userspace installed a new fd."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/vhost/vdpa.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "776f395004d829bbbf18c159ed9beb517a208c71",
"lessThan": "e260dc9fbfdae0978e7a8698f977fbb463a657be",
"versionType": "git",
"status": "affected"
},
{
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"lessThan": "66e73fa18910b39fea0941dea5fe091122240855",
"versionType": "git",
"status": "affected"
},
{
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"versionType": "git",
"status": "affected"
},
{
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"status": "affected"
},
{
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"versionType": "git",
"status": "affected"
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{
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{
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{
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}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/vhost/vdpa.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.8",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.8",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.271",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.222",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.189",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.158",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.111",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.53",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.7",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/388c678639a0cebfd936b3e56c64ac6a371efec2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4fde085eb839fbb39c25cbba5d2a091ded394877",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/59fc7c1c6b4d325194ca45352180340092d95098",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/65faf9eaa00e408e1406fbcf675c8c8d0e27ff2a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/e74a9fa50749b9940b4fb13199652325e08d3c4a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}