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CVE-2026-68441— net/sched: Handle TC_ACT_REDIRECT from qdisc filter chains

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于对TC_ACT_REDIRECT处理不当，当qdisc过滤器链返回该结果时，qdisc分类函数未处理重定向，导致数据包被静默转发而非重定向，且bpf_redirect()在bpf_net_context未设置时可能导致空指针解引用，进而引发拒绝服务。

AI Predicted 5.3 Difficulty: Easy EPSS 0.16% · P5

Affected Version Matrix 8

VendorProduct Version RangeStatus
Linux Linux 27b29f63058d26c6c1742f1993338280d5a41dc6< 9cbad9c8125f5fe377c0800ab08f7196eab44456 affected
27b29f63058d26c6c1742f1993338280d5a41dc6< c8fd74445e86f88096d2f6cf0f9e4d54d8ed1781 affected
27b29f63058d26c6c1742f1993338280d5a41dc6< ec48b3be2c8595dd290be883dbd4fb8b2f9f5d5e affected
4.4 affected
< 4.4 unaffected
6.18.57≤ 6.18.* unaffected
7.1.6≤ 7.1.* unaffected
7.2≤ * unaffected
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I. Basic Information for CVE-2026-68441

Vulnerability Information
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Vulnerability Title
net/sched: Handle TC_ACT_REDIRECT from qdisc filter chains
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: Handle TC_ACT_REDIRECT from qdisc filter chains When a TC filter attached to a qdisc filter chain returns TC_ACT_REDIRECT (ex: via an eBPF program calling bpf_redirect() or an act_bpf action), the redirect was silently lost i.e no qdisc classify function handled TC_ACT_REDIRECT, so the packet fell through the switch and was enqueued normally instead of being redirected. This has been broken since bpf_redirect() was introduced for TC in commit 27b29f63058d ("bpf: add bpf_redirect() helper"). We got lucky for a long time because bpf_net_context was a per-CPU variable that was always available. commit 401cb7dae813 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.") turned bpf_net_context into a task_struct member that is only set up by explicit callers. Without a caller setting it up, bpf_redirect() itself crashes with a NULL pointer dereference in bpf_net_ctx_get_ri(). However, even with bpf_net_context available, TC_ACT_REDIRECT from qdisc filter chains cannot be honored without adding skb_do_redirect() calls to every qdisc classify function, which would require changes across net/sched/. Isolate it to ebpf core where it belongs. Instead, add a tcf_classify_qdisc() inline helper in pkt_cls.h, as a wrapper around tcf_classify() for use by qdisc classify functions and tcf_qevent_handle(). When the classify verdict is TC_ACT_REDIRECT, the wrapper converts it to TC_ACT_SHOT, dropping the packet rather than letting it continue silently. Dropping is preferred over letting the packet through because the user immediately sees packet loss. Silently passing the packet through would hide the problem and leave the user wondering why their redirect is not working. The clsact fast path, tc_run() continues to call tcf_classify() directly and is unaffected: TC_ACT_REDIRECT is returned as-is and handled by sch_handle_egress/ingress() calling skb_do_redirect() as before.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于对TC_ACT_REDIRECT处理不当，当qdisc过滤器链返回该结果时，qdisc分类函数未处理重定向，导致数据包被静默转发而非重定向，且bpf_redirect()在bpf_net_context未设置时可能导致空指针解引用，进而引发拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 27b29f63058d26c6c1742f1993338280d5a41dc6 ~ 9cbad9c8125f5fe377c0800ab08f7196eab44456 -
Linux Linux 4.4 -

II. Public POCs for CVE-2026-68441

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III. Intelligence Information for CVE-2026-68441

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Patches & Fixes for CVE-2026-68441 (2)

Other References for CVE-2026-68441 (1)

Same Patch Batch · Linux · 2026-08-12 · 22 CVEs total

CVE-2026-68431 9.1 CRITICAL ksmbd: validate minimum PDU size for transform requests
CVE-2026-68432 8.8 HIGH vxlan: require CAP_NET_ADMIN in the device netns for changelink
CVE-2026-68433 8.6 HIGH libceph: bound get_version reply decode to front len
CVE-2026-68446 7.8 HIGH drm/vmwgfx: Validate vmw_surface_metadata::array_size
CVE-2026-68445 7.8 HIGH drm/vc4: Prevent shader BO mappings from becoming writable
CVE-2026-68440 7.8 HIGH net: txgbe: fix heap overflow when reading module EEPROM
CVE-2026-68442 7.8 HIGH btrfs: don't propagate EXTENT_FLAG_LOGGING to split extent maps
CVE-2026-68447 7.1 HIGH drm/amdkfd: clamp v9 CRIU control stack checkpoint copy to BO size
CVE-2026-68439 wifi: mt76: mt7925: fix possible NULL-pointer deref in mt7925_mcu_bss_he_tlv()
CVE-2026-68450 btrfs: free mapping node on duplicate reloc root insert
CVE-2026-68449 ata: sata_dwc_460ex: fix infinite loop in NCQ tag completion bit-scanning
CVE-2026-68448 ovl: check access to copy_file_range source with src mounter creds
CVE-2026-68444 firmware: arm_ffa: Fix NULL dereference in ffa_partition_info_get()
CVE-2026-68443 hwmon: (gigabyte_waterforce) Stop device IO before calling hid_hw_stop
CVE-2026-68429 drm/dp_mst: Handle torn-down topology gracefully in drm_dp_mst_topology_queue_probe()
CVE-2026-68438 smp: Make CSD lock acquisition atomic for debug mode
CVE-2026-68437 drm/imagination: Fit paired fragment job in the correct CCCB
CVE-2026-68436 drm/amd/display: use kvzalloc to allocate struct dc
CVE-2026-68435 LoongArch: Fix address space mismatch in kexec command line lookup
CVE-2026-68434 serial: 8250_mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms

Showing top 20 of 22 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-68441

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