net: reject oversized tx_queue_len at netlink parse time
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.160, 6.12.111, 6.18.53, 7.2.7
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: net: reject oversized tx_queue_len at netlink parse time rtnl_create_link() assigns IFLA_TXQLEN directly to dev->tx_queue_len without going through netif_change_tx_queue_len(), so a device created with "ip link add ... txqueuelen 500000" bypasses the S16_MAX cap and still triggers the oversized ring allocations in pfifo_fast, tun and tap. The veth peer nest (rtnl_nla_parse_ifinfomsg()) and the RTM_NEWLINK-on-existing-device path reach the same sinks. Enforce the cap in ifla_policy instead: IFLA_TXQLEN becomes NLA_POLICY_FULL_RANGE(NLA_U32, &txqlen_range) with txqlen_range = { .min = 0, .max = S16_MAX }. All netlink consumers parse against this policy - rtnl_setlink(), rtnl_newlink() (create and change), and the veth peer nest - so every netlink path is capped at parse time and rejects the attribute with -ERANGE plus a proper "integer out of range" extack message before any device state is modified (the RTM_SETLINK half-application wart is gone with it). Document the bound in the rt-link.yaml netlink spec. Conditions to recreate the bug: • CONFIG_NET_SCHED=y, CONFIG_VETH=y, CONFIG_USER_NS=y, CONFIG_NET_NS=y. • Unprivileged user in a fresh user+net namespace (unshare -Urn): ip link add v0 txqueuelen 500000 type veth peer name v1 -> on the fixed kernel this is rejected with -ERANGE ("integer out of range" extack) instead of installing an oversized tx_queue_len that later inflates pfifo_fast/tun/tap ring allocations. • ip link set v0 txqueuelen 500000 is likewise rejected at parse time.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 38f7b870d4a6a5d3ec21557e849620cb7d032965 · fixed in 26ee5f99ffe7ab98e635071290eff14192e9e34a; From 38f7b870d4a6a5d3ec21557e849620cb7d032965 · fixed in 45ca9f59b6c7ea70e0a17054902b8a556913db34; From 38f7b870d4a6a5d3ec21557e849620cb7d032965 · fixed in 2fd0880f0272ec022906a05587fd91416ebecc38; From 38f7b870d4a6a5d3ec21557e849620cb7d032965 · fixed in a638a2625aa83160a394abe8e8b2e524a80c771b; From 38f7b870d4a6a5d3ec21557e849620cb7d032965 · fixed in 1aa9e143bf51405665a793d4cc925e1c4f0c5922
- Linux Linux
2.6.23
- KernelLinux
From 2.6.23 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53; From 6.19.0 · fixed in 7.2.7