sch/netem: fix use after free in netem_dequeue
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: sch/netem: fix use after free in netem_dequeue If netem_dequeue() enqueues packet to inner qdisc and that qdisc returns __NET_XMIT_STOLEN. The packet is dropped but qdisc_tree_reduce_backlog() is not called to update the parent's q.qlen, leading to the similar use-after-free as Commit e04991a48dbaf382 ("netem: fix return value if duplicate enqueue fails") Commands to trigger KASAN UaF: ip link add type dummy ip link set lo up ip link set dummy0 up tc qdisc add dev lo parent root handle 1: drr tc filter add dev lo parent 1: basic classid 1:1 tc class add dev lo classid 1:1 drr tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2: handle 3: drr tc filter add dev lo parent 3: basic classid 3:1 action mirred egress redirect dev dummy0 tc class add dev lo classid 3:1 drr ping -c1 -W0.01 localhost # Trigger bug tc class del dev lo classid 1:1 tc class add dev lo classid 1:1 drr ping -c1 -W0.01 localhost # UaF
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.3 and later | 4.19.322, 5.4.284, 5.10.226, 5.15.167, 6.1.110, 6.6.51, 6.10.10, 6.11 | Patch available | CNA |
- Linux VendorLinux Affected 3.3 and later Fixed in 4.19.322, 5.4.284, 5.10.226, 5.15.167, 6.1.110, 6.6.51, 6.10.10, 6.11 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.3 to before 4.19.322; 4.20 to before 5.4.284; 5.5 to before 5.10.226; 5.11 to before 5.15.167; 5.16 to before 6.1.110; 6.2 to before 6.6.51; 6.7 to before 6.10.10 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* | 6.11 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* | 6.11 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:* | 6.11 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:* | 6.11 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc5:*:*:*:*:*:* | 6.11 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc6:*:*:*:*:*:* | 6.11 rc6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.3 to before 4.19.322; 4.20 to before 5.4.284; 5.5 to before 5.10.226; 5.11 to before 5.15.167; 5.16 to before 6.1.110; 6.2 to before 6.6.51; 6.7 to before 6.10.10 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* Versions 6.11 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* Versions 6.11 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:* Versions 6.11 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:* Versions 6.11 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc5:*:*:*:*:*:* Versions 6.11 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc6:*:*:*:*:*:* Versions 6.11 rc6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.19.322, 5.4.284, 5.10.226, 5.15.167, 6.1.110, 6.6.51, 6.10.10, 6.11
Red Hat 1 advisory
- RHSA-2025:6966 Released 2025-05-13 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-570.12.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.12.1.el9_6, kernel-64k-devel-5.14.0-570.12.1.el9_6 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-570.12.1.el9_6, kernel-64k-5.14.0-570.12.1.el9_6, kernel-64k-core-5.14.0-570.12.1.el9_6 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-570.12.1.el9_6, libperf-5.14.0-570.12.1.el9_6
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-64k-5.14.0-570.12.1.el9_6, kernel-rt-64k-core-5.14.0-570.12.1.el9_6 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-core-5.14.0-570.12.1.el9_6, kernel-rt-debug-5.14.0-570.12.1.el9_6 +11
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2025:6966 |
Timeline
- 2026-10-02 Threatist record created from CVE-2024-46800
- 2026-10-03 Alias added: GHSA-gwcv-998j-qccx
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/f0bddb4de043399f16d1969dad5ee5b984a64e7b
- https://git.kernel.org/stable/c/295ad5afd9efc5f67b86c64fce28fb94e26dc4c9
- https://git.kernel.org/stable/c/98c75d76187944296068d685dfd8a1e9fd8c4fdc
- https://git.kernel.org/stable/c/14f91ab8d391f249b845916820a56f42cf747241
- https://git.kernel.org/stable/c/db2c235682913a63054e741fe4e19645fdf2d68e
- https://git.kernel.org/stable/c/dde33a9d0b80aae0c69594d1f462515d7ff1cb3d
- https://git.kernel.org/stable/c/32008ab989ddcff1a485fa2b4906234c25dc5cd6
- https://git.kernel.org/stable/c/3b3a2a9c6349e25a025d2330f479bc33a6ccb54a
More Linux Kernel vulnerabilities
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-46800 · CVE Program
- CVE-2024-46800 · NVD
- FIRST EPSS
- GHSA-gwcv-998j-qccx · GitHub Advisory Database · CC BY 4.0
- CVE-2024-46800 · Red Hat security data · CC BY 4.0
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