Answer in brief
CVE-2026-74310 records a Unknown severity vulnerability in vhost/net: complete zerocopy ubufs only once. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=bab632d69ee48a106e779b60cc01adfe80a72807 <ea71f873423fb73e66ad88936d6759ac0ad4aa53 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <6445b945024f4c7675ae5352b2d5885cb1deea71 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d || >=bab632d69ee48a106e779b60cc01adfe80a72807 <321c73baf54d971ce3771fea275c98a247f7ee35 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <c069437924663539a93a1e5afe90838d9ccee284 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <8f6898fe80794f2d7c3d38c1158c806e4074a1c4 | ea71f873423fb73e66ad88936d6759ac0ad4aa53, 6445b945024f4c7675ae5352b2d5885cb1deea71, a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d, 321c73baf54d971ce3771fea275c98a247f7ee35, c069437924663539a93a1e5afe90838d9ccee284, 8f6898fe80794f2d7c3d38c1158c806e4074a1c4 |
| Linux/Linuxgeneric | 3.1 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
In the Linux kernel, the following vulnerability has been resolved: vhost/net: complete zerocopy ubufs only once vhost-net initializes one ubuf_info per outstanding zerocopy TX descriptor and hands it to the backend socket. The networking stack may then clone a zerocopy skb before all skb references are released. For example, batman-adv fragmentation reaches skb_split(), which calls skb_zerocopy_clone() and increments the same ubuf_info refcount. vhost_zerocopy_complete() currently treats every ubuf callback as a completed vhost descriptor. It dereferences ubuf->ctx, writes the descriptor completion state, and drops the vhost_net_ubuf_ref even when the callback only releases a cloned skb reference. A backend reset can therefore wait for and free the vhost_net_ubuf_ref while another cloned skb still carries the same ubuf_info. A later completion then dereferences the freed ubufs pointer. KASAN reports the stale completion as: BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x1d7/0x1f0 BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x101/0x1f0 vhost_zerocopy_complete skb_copy_ubufs __dev_forward_skb2 veth_xmit The freed object was allocated from vhost_net_ioctl() while setting the backend and freed through kfree_rcu()/kvfree_rcu_bulk after backend removal, while delayed skb completion still reached vhost_zerocopy_complete(). Honor the generic ubuf_info refcount before touching vhost state, and run the vhost descriptor completion only for the final ubuf reference. This matches the msg_zerocopy_complete() ownership rule for cloned zerocopy skbs.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-74310 records a Unknown severity vulnerability in vhost/net: complete zerocopy ubufs only once. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=bab632d69ee48a106e779b60cc01adfe80a72807 <ea71f873423fb73e66ad88936d6759ac0ad4aa53 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <6445b945024f4c7675ae5352b2d5885cb1deea71 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d || >=bab632d69ee48a106e779b60cc01adfe80a72807 <321c73baf54d971ce3771fea275c98a247f7ee35 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <c069437924663539a93a1e5afe90838d9ccee284 || >=bab632d69ee48a106e779b60cc01adfe80a72807 <8f6898fe80794f2d7c3d38c1158c806e4074a1c4 | ea71f873423fb73e66ad88936d6759ac0ad4aa53, 6445b945024f4c7675ae5352b2d5885cb1deea71, a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d, 321c73baf54d971ce3771fea275c98a247f7ee35, c069437924663539a93a1e5afe90838d9ccee284, 8f6898fe80794f2d7c3d38c1158c806e4074a1c4 |
| Linux/Linuxgeneric | 3.1 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
In the Linux kernel, the following vulnerability has been resolved: vhost/net: complete zerocopy ubufs only once vhost-net initializes one ubuf_info per outstanding zerocopy TX descriptor and hands it to the backend socket. The networking stack may then clone a zerocopy skb before all skb references are released. For example, batman-adv fragmentation reaches skb_split(), which calls skb_zerocopy_clone() and increments the same ubuf_info refcount. vhost_zerocopy_complete() currently treats every ubuf callback as a completed vhost descriptor. It dereferences ubuf->ctx, writes the descriptor completion state, and drops the vhost_net_ubuf_ref even when the callback only releases a cloned skb reference. A backend reset can therefore wait for and free the vhost_net_ubuf_ref while another cloned skb still carries the same ubuf_info. A later completion then dereferences the freed ubufs pointer. KASAN reports the stale completion as: BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x1d7/0x1f0 BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x101/0x1f0 vhost_zerocopy_complete skb_copy_ubufs __dev_forward_skb2 veth_xmit The freed object was allocated from vhost_net_ioctl() while setting the backend and freed through kfree_rcu()/kvfree_rcu_bulk after backend removal, while delayed skb completion still reached vhost_zerocopy_complete(). Honor the generic ubuf_info refcount before touching vhost state, and run the vhost descriptor completion only for the final ubuf reference. This matches the msg_zerocopy_complete() ownership rule for cloned zerocopy skbs.
Quoted source text, attributed separately from HOL analysis.