CVE-2026-98419

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

drop_monitor: fix out-of-bounds write in reset_per_cpu_data()

In reset_per_cpu_data(), al is computed as:

al = sizeof(struct net_dm_alert_msg);

al += dm_hit_limit * sizeof(struct net_dm_drop_point);

al += sizeof(struct nlattr);

skb = genlmsg_new(al, GFP_KERNEL);

...

nla = nla_reserve(skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg));

...

msg = nla_data(nla);

memset(msg, 0, al);

Because al includes sizeof(struct nlattr) (the 4-byte attribute header),

genlmsg_new() allocates al bytes of tailroom starting at nla.

However, msg points to nla_data(nla), which is located

sizeof(struct nlattr) bytes past nla. Calling memset(msg, 0, al)

therefore writes al bytes starting from msg, exceeding the allocated

buffer by sizeof(struct nlattr) (4 bytes) and corrupting

skb_shared_info.

Fix this by letting al represent only the payload length, allocating

the skb with genlmsg_new(nla_total_size(al

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References