ipv6: prevent in6_dev_get() from resurrecting inet6_dev
Summary
| CVE | CVE-2026-74630 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-22 16:16:35 UTC |
| Updated | 2026-08-22 16:16:35 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent in6_dev_get() from resurrecting inet6_dev in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed. Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller. An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000: refcount_t: addition on 0; use-after-free. ip6_mc_source+0xef4/0x17e0 It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends: BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0 Write of size 8 at addr ffff888015b50240 by task poc/1219 Bug found and triaged by OpenAI Security Research and validated by Trail of Bits. |
Risk And Classification
EPSS: 0.002200000 probability, percentile 0.127420000 (date 2026-08-23)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 785d908f8d21c8bc78b6fb2c2932ab662bf6918a git | Not specified |
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8 git | Not specified |
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 145812b678de9f3b59780173be3c0d22ed60dd93 git | Not specified |
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 cc5bd568f9b7683e60841b6fd02c10d64535bd6e git | Not specified |
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 1c206d461c680c3151daa3c89fc26eaf5bf98a7f git | Not specified |
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 680fbd7942185448eadb990a3d10a53eb946b702 git | Not specified |
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 14e812ab41df0cac033479da835ec9a5de633404 git | Not specified |
| CNA | Linux | Linux | affected 8814c4b533817df825485ff32ce6ac406c3a54d1 0e243671bc7b8eaf00f83dd2f4367436dc0cff98 git | Not specified |
| CNA | Linux | Linux | affected 2.6.19 | Not specified |
| CNA | Linux | Linux | unaffected 2.6.19 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.265 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.216 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.183 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.152 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.104 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.45 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.9 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93 | 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.