CVE catalog

CVE-2026-45949

In the Linux kernel, the following vulnerability has been resolved: hwrng: core - use RCU and work_struct to fix race condition Currently, hwrng_fill is not cleared until the hwrng_fillfn() thread e

[CVE catalog]

Severity: Medium · CVSS 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Published: May 27, 2026, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.09% · Oct 25, 2026

In the Linux kernel, the following vulnerability has been resolved: hwrng: core - use RCU and work_struct to fix race condition Currently, hwrng_fill is not cleared until the hwrng_fillfn() thread exits. Since hwrng_unregister() reads hwrng_fill outside the rng_mutex lock, a concurrent hwrng_unregister() may call kthread_stop() again on the same task. Additionally, if hwrng_unregister() is called immediately after hwrng_register(), the stopped thread may have never been executed. Thus, hwrng_fill remains dirty even after hwrng_unregister() returns. In this case, subsequent calls to hwrng_register() will fail to start new threads, and hwrng_unregister() will call kthread_stop() on the same freed task. In both cases, a use-after-free occurs: refcount_t: addition on 0; use-after-free. WARNING: ... at lib/refcount.c:25 refcount_warn_saturate+0xec/0x1c0 Call Trace: kthread_stop+0x181/0x360 hwrng_unregister+0x288/0x380 virtrng_remove+0xe3/0x200 This patch fixes the race by protecting the global hwrng_fill pointer inside the rng_mutex lock, so that hwrng_fillfn() thread is stopped only once, and calls to kthread_run() and kthread_stop() are serialized with the lock held. To avoid deadlock in hwrng_fillfn() while being stopped with the lock held, we convert current_rng to RCU, so that get_current_rng() can read current_rng without holding the lock. To remove the lock from put_rng(), we also delay the actual cleanup into a work_struct. Since get_current_rng() no longer returns ERR_PTR values, the IS_ERR() checks are removed from its callers. With hwrng_fill protected by the rng_mutex lock, hwrng_fillfn() can no longer clear hwrng_fill itself. Therefore, if hwrng_fillfn() returns directly after current_rng is dropped, kthread_stop() would be called on a freed task_struct later. To fix this, hwrng_fillfn() calls schedule() now to keep the task alive until being stopped. The kthread_stop() call is also moved from hwrng_unregister() to drop_current_rng(), ensuring kthread_stop() is called on all possible paths where current_rng becomes NULL, so that the thread would not wait forever.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	linux	sid	`7.2.12-1`	fixed
Debian	linux	forky	`7.2.12-1`	fixed
Debian	linux	trixie	`6.12.107-1`	fixed
Debian	linux	trixie-security	`6.12.113-1`	fixed
Debian	linux	bookworm	`6.1.176-1`	vulnerable
Debian	linux	bookworm-security	`6.1.190-1`	vulnerable
Cpe	linux	Not reported	Not reported	vulnerable
Cpe	linux_kernel	Not reported	`6.12.75`	fixed
Cpe	linux_kernel	Not reported	`6.18.14`	fixed
Cpe	linux_kernel	Not reported	`6.19.4`	fixed
Cpe	linux_kernel	Not reported	`6.19.4`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	linux	source	sid	`6.18.14-1`	not yet assigned	Not reported	Not reported
Debian	linux	source	forky	`6.18.14-1`	not yet assigned	Not reported	Not reported
Debian	linux	source	trixie	`6.12.85-1`	not yet assigned	Not reported	Not reported
Debian	linux	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported
Cpe	linux_kernel	cpe	Not reported	`6.12.75`	Not reported	Not reported	Not reported
Cpe	linux_kernel	cpe	Not reported	`6.18.14`	Not reported	Not reported	Not reported
Cpe	linux_kernel	cpe	Not reported	`6.19.4`	Not reported	Not reported	Not reported
Cpe	linux_kernel	cpe	Not reported	`6.19.4`	Not reported	NVD-CVE-2026-45949	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[bpftool]Affected
Source package: [linux]
Details (6)
- 7.1.0+6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 7.1.0+6.1.176-1 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 7.5.0+6.12.95-1~bpo12+1 · amd64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 7.5.0+6.12.95-1~bpo12+1 · arm64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 7.1.0+6.1.180-1 · amd64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 7.1.0+6.1.180-1 · arm64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[hyperv-daemons]Affected
Source package: [linux]
Details (6)
- 6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · amd64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · arm64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · amd64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · arm64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[intel-sdsi]Affected
Source package: [linux]
Details (1)
- 6.12.95-1~bpo12+1 · amd64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[libcpupower1]Affected
Source package: [linux]
Details (6)
- 6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · amd64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · arm64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · amd64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · arm64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[libcpupower-dev]Affected
Source package: [linux]
Details (6)
- 6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · amd64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · arm64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · amd64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · arm64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-bpf-dev]Affected
Source package: [linux]
Details (2)
- 6.12.95-1~bpo12+1 · amd64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · arm64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-compiler-gcc-12-x86]Affected
Source package: [linux]
Details (2)
- 6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · amd64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-config-6.1]Affected
Source package: [linux]
Details (4)
- 6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · amd64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · arm64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-cpupower]Affected
Source package: [linux]
Details (6)
- 6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · amd64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · arm64 · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · amd64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · arm64 · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-doc]Affected
Source package: [linux]
Details (32)
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.43-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.43-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.57-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.57-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.63-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.63-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.69-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.69-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.73-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.73-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.74-2~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.74-2~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.85-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.85-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.86-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.86-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.88-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.88-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.90-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.90-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.90-2~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.90-2~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.94-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.94-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.12.95-1~bpo12+1 · all · bookworm-backports
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · all · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · all · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-doc-6.1]Affected
Source package: [linux]
Details (6)
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.176-1 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · all · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.180-1 · all · bookworm-security
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-amd64]Affected
Source package: [linux]
Details (1)
- 6.1.170-3 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-arm64]Affected
Source package: [linux]
Details (1)
- 6.1.170-3 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-cloud-amd64]Affected
Source package: [linux]
Details (1)
- 6.1.170-3 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-cloud-arm64]Affected
Source package: [linux]
Details (1)
- 6.1.170-3 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-common]Affected
Source package: [linux]
Details (2)
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-common-rt]Affected
Source package: [linux]
Details (2)
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
- 6.1.170-3 · all · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-rt-amd64]Affected
Source package: [linux]
Details (1)
- 6.1.170-3 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-47-rt-arm64]Affected
Source package: [linux]
Details (1)
- 6.1.170-3 · arm64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12
[linux-headers-6.1.0-50-amd64]Affected
Source package: [linux]
Details (1)
- 6.1.176-1 · amd64 · bookworm
  Affected
  nvd · linux · debian · bookworm; nvd · linux · debian · 12

Next results

Observed: Oct 27, 2026, 7:21:12 AM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]