CVE-2026-74734
In the Linux kernel, the following vulnerability has been resolved:
firewire: ohci: fix NULL pointer dereference in ar_context_release
During the error handling path of the driver's probe function, a NULL pointer dereference can occur in ar_context_release().
When pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping fails), the devres cleanup mechanism invokes release_ohci(). This function unconditionally calls ar_context_release() to clean up the asynchronous receive contexts. However, if ar_context_init() was not yet called, ctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by devres_alloc()).
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ar_context_release() immediately dereferences ctx->ohci to get the dev pointer before checking if the context was actually initialized, leading to a crash:
To fix this, move the assignment of the dev pointer after the !ctx->buffer check. If ctx->buffer is NULL, it indicates that the context was never successfully initialized and there is nothing to release, safely avoiding the dereference of the uninitialized ctx->ohci pointer.
Detalles técnicos trazas, registros y código del informe original
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543 Call Trace: release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567 release_nodes drivers/base/devres.c:546 [inline] devres_release_all+0x1a8/0x260 drivers/base/devres.c:576 device_unbind_cleanup drivers/base/dd.c:597 [inline] really_probe+0x451/0xae0 drivers/base/dd.c:772
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.21%
- Percentil entre todas las CVEs puntuadas: 10
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-74734",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5716e58aecdd4f7225c2e46ce903a839fc54f22f",
"lessThan": "ed5470771c7ed7f959230c4697f316af83426a90",
"versionType": "git"
},
{
"status": "affected",
"version": "5716e58aecdd4f7225c2e46ce903a839fc54f22f",
"lessThan": "7d228ba43279de2d191f25e139fad166409c2c06",
"versionType": "git"
},
{
"status": "affected",
"version": "5716e58aecdd4f7225c2e46ce903a839fc54f22f",
"lessThan": "42d217add8d80d6e7d9f58f80d11ea9b07ea113e",
"versionType": "git"
}
],
"programFiles": [
"drivers/firewire/ohci.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.5"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.5",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.10",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/firewire/ohci.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-08-26T15:16:51.927",
"references": [
{
"url": "https://git.kernel.org/stable/c/42d217add8d80d6e7d9f58f80d11ea9b07ea113e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7d228ba43279de2d191f25e139fad166409c2c06",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ed5470771c7ed7f959230c4697f316af83426a90",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfirewire: ohci: fix NULL pointer dereference in ar_context_release\n\nDuring the error handling path of the driver's probe function, a NULL\npointer dereference can occur in ar_context_release().\n\nWhen pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping\nfails), the devres cleanup mechanism invokes release_ohci(). This function\nunconditionally calls ar_context_release() to clean up the asynchronous\nreceive contexts. However, if ar_context_init() was not yet called,\nctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by\ndevres_alloc()).\n\nar_context_release() immediately dereferences ctx->ohci to get the dev\npointer before checking if the context was actually initialized, leading to\na crash:\n\nOops: general protection fault, probably for non-canonical address\n0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\nRIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543\nCall Trace:\n release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567\n release_nodes drivers/base/devres.c:546 [inline]\n devres_release_all+0x1a8/0x260 drivers/base/devres.c:576\n device_unbind_cleanup drivers/base/dd.c:597 [inline]\n really_probe+0x451/0xae0 drivers/base/dd.c:772\n\nTo fix this, move the assignment of the dev pointer after the !ctx->buffer\ncheck. If ctx->buffer is NULL, it indicates that the context was never\nsuccessfully initialized and there is nothing to release, safely avoiding\nthe dereference of the uninitialized ctx->ohci pointer."
}
],
"lastModified": "2026-08-26T15:16:51.927",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}