VulnerabilityPublished 26 Aug 2026Updated 21 Oct 2026

CVE-2026-74734: Linux kernel · firewire: ohci: fix NULL pointer dereference in ar_context_release

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in ed5470771c7ed7f959230c4697f316af83426a90 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:07 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in ed5470771c7ed7f959230c4697f316af83426a90, ca2fa74f3200ced6e0a940753ad99844c42ad7c8, 3770a4794a14331c8ca6a674e49c021827521c2c +2

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 5716e58aecdd4f7225c2e46ce903a839fc54f22f, < ed5470771c7ed7f959230c4697f316af83426a90	Fixed in ed5470771c7ed7f959230c4697f316af83426a90
LinuxLinux	Affected ≥ 5716e58aecdd4f7225c2e46ce903a839fc54f22f, < ca2fa74f3200ced6e0a940753ad99844c42ad7c8	Fixed in ca2fa74f3200ced6e0a940753ad99844c42ad7c8
LinuxLinux	Affected ≥ 5716e58aecdd4f7225c2e46ce903a839fc54f22f, < 3770a4794a14331c8ca6a674e49c021827521c2c	Fixed in 3770a4794a14331c8ca6a674e49c021827521c2c
LinuxLinux	Affected ≥ 5716e58aecdd4f7225c2e46ce903a839fc54f22f, < 42d217add8d80d6e7d9f58f80d11ea9b07ea113e	Fixed in 42d217add8d80d6e7d9f58f80d11ea9b07ea113e
LinuxLinux	Affected ≥ 5716e58aecdd4f7225c2e46ce903a839fc54f22f, < 7d228ba43279de2d191f25e139fad166409c2c06	Fixed in 7d228ba43279de2d191f25e139fad166409c2c06
LinuxLinux	Affected =6.5	Fixed in–

Description

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()). ar_context_release() immediately dereferences ctx->ohci to get the dev pointer before checking if the context was actually initialized, leading to a crash: 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 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.

References

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