CVE-2026-31422net/sched: cls_flow: fix NULL pointer dereference on shared blocks
Updated under an hour ago ()
Does this affect you?
It affects Linux and 4 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_flow: fix NULL pointer dereference on shared blocks flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block. Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below: ======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...] =======================================================================
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 1abf272022cf1d18469405f47b4ec49c6a3125db before 57f94ac7e953eece5ed4819605a18f3cdfc63dcc; from 1abf272022cf1d18469405f47b4ec49c6a3125db before 942813276edeb1741fa5b0a73471beb4e495fa08; from 1abf272022cf1d18469405f47b4ec49c6a3125db before cc707a4fd4c3b6ab2722e06bc359aa010e13d408; from 1abf272022cf1d18469405f47b4ec49c6a3125db before 4a09f72007201c9f667dc47f64517ec23eea65e5; from 1abf272022cf1d18469405f47b4ec49c6a3125db before 9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e; from 1abf272022cf1d18469405f47b4ec49c6a3125db before a208c3e1232997e9317887294c20008dfcb75449; from 1abf272022cf1d18469405f47b4ec49c6a3125db before 415ea0c973c754b9f375225807810eb9045f4293; 1abf272022cf1d18469405f47b4ec49c6a3125db builds before 1a280dd4bd1d616a01d6ffe0de284c907b555504 | CNA record |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
linux linux_kernel linux:linux_kernel | from 4.15 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.134; from 6.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0; and 5 more ranges | NVD |
References
- https://git.kernel.org/stable/c/57f94ac7e953eece5ed4819605a18f3cdfc63dccpatch
- https://git.kernel.org/stable/c/942813276edeb1741fa5b0a73471beb4e495fa08patch
- https://git.kernel.org/stable/c/cc707a4fd4c3b6ab2722e06bc359aa010e13d408patch
- https://git.kernel.org/stable/c/4a09f72007201c9f667dc47f64517ec23eea65e5patch
- https://git.kernel.org/stable/c/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957epatch
- https://git.kernel.org/stable/c/a208c3e1232997e9317887294c20008dfcb75449patch
- https://git.kernel.org/stable/c/415ea0c973c754b9f375225807810eb9045f4293patch
- https://git.kernel.org/stable/c/1a280dd4bd1d616a01d6ffe0de284c907b555504patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.