CVE-2024-45016

netem: fix return value if duplicate enqueue fails

State: Published
Severity: 7.8 High
Published: Sep 11, 2024
Updated: Oct 15, 2026
Reserved: Aug 21, 2024

Description

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

netem: fix return value if duplicate enqueue fails

There is a bug in netem_enqueue() introduced by commit 5845f706388a ("net: netem: fix skb length BUG_ON in __skb_to_sgvec") that can lead to a use-after-free.

This commit made netem_enqueue() always return NET_XMIT_SUCCESS when a packet is duplicated, which can cause the parent qdisc's q.qlen to be mistakenly incremented. When this happens qlen_notify() may be skipped on the parent during destruction, leaving a dangling pointer for some classful qdiscs like DRR.

There are two ways for the bug happen:

- If the duplicated packet is dropped by rootq->enqueue() and then the original packet is also dropped. - If rootq->enqueue() sends the duplicated packet to a different qdisc and the original packet is dropped.

In both cases NET_XMIT_SUCCESS is returned even though no packets are enqueued at the netem qdisc.

The fix is to defer the enqueue of the duplicate packet until after the original packet has been guaranteed to return NET_XMIT_SUCCESS.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 759e3e8c4a6a6b4e52ebc4547123a457f0ce90d4Affected 5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before c414000da1c2ea1ba9a5e5bb1a4ba774e51e202dAffected 5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 52d99a69f3d556c6426048c9d481b912205919d8Affected 5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 0486d31dd8198e22b63a4730244b38fffce6d469Affected 5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 577d6c0619467fe90f7e8e57e45cb5bd9d936014Affected 5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before e5bb2988a310667abed66c7d3ffa28880cf0f883Affected 5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before c07ff8592d57ed258afee5a5e04991a48dbaf382Affected a550a01b8af856f2684b0f79d552f5119eb5006cAffected 009510a90e230bb495f3fe25c7db956679263b07Affected 4de7d30668cb8b06330992e1cd336f91700a2ce7Affected d1dd2e15c85e890a1cc9bde5ba07ae63331e5c73Affected 0148fe458b5705e2fea7cb88294fed7e36066ca2Affected 3.16.66 to before 3.17Affected 4.9.163 to before 4.10Affected 4.14.106 to before 4.15Affected 4.19.28 to before 4.20Affected 4.20.15 to before 4.21Affected
LinuxLinux	5.0Affected before 5.0Not affected 5.4.283 through 5.4.Not affected 5.10.225 through 5.10.Not affected 5.15.166 through 5.15.Not affected 6.1.107 through 6.1.Not affected 6.6.48 through 6.6.Not affected 6.10.7 through 6.10.Not affected 6.11 and laterNot affected

Product

Versions

LinuxLinux

5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 759e3e8c4a6a6b4e52ebc4547123a457f0ce90d4Affected
5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before c414000da1c2ea1ba9a5e5bb1a4ba774e51e202dAffected
5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 52d99a69f3d556c6426048c9d481b912205919d8Affected
5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 0486d31dd8198e22b63a4730244b38fffce6d469Affected
5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before 577d6c0619467fe90f7e8e57e45cb5bd9d936014Affected
5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before e5bb2988a310667abed66c7d3ffa28880cf0f883Affected
5845f706388a4cde0f6b80f9e5d33527e942b7d9 to before c07ff8592d57ed258afee5a5e04991a48dbaf382Affected
a550a01b8af856f2684b0f79d552f5119eb5006cAffected
009510a90e230bb495f3fe25c7db956679263b07Affected
4de7d30668cb8b06330992e1cd336f91700a2ce7Affected
d1dd2e15c85e890a1cc9bde5ba07ae63331e5c73Affected
0148fe458b5705e2fea7cb88294fed7e36066ca2Affected
3.16.66 to before 3.17Affected
4.9.163 to before 4.10Affected
4.14.106 to before 4.15Affected
4.19.28 to before 4.20Affected
4.20.15 to before 4.21Affected

LinuxLinux

5.0Affected
before 5.0Not affected
5.4.283 through 5.4.*Not affected
5.10.225 through 5.10.*Not affected
5.15.166 through 5.15.*Not affected
6.1.107 through 6.1.*Not affected
6.6.48 through 6.6.*Not affected
6.10.7 through 6.10.*Not affected
6.11 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.