CVE-2026-31421
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2026
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
net/sched: cls_fw: fix NULL pointer dereference on shared blocks
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_fw: fix NULL pointer dereference on shared blocks The old-method path in fw_classify() calls tcf_block_q() and dereferences q->handle. Shared blocks leave block->q NULL, causing a NULL deref when an empty cls_fw filter is attached to a shared block and a packet with a nonzero major skb mark is classified. Reject the configuration in fw_change() when the old method (no TCA_OPTIONS) is used on a shared block, since fw_classify()'s old-method path needs block->q which is NULL for shared blocks. The fixed null-ptr-deref calling stack: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:fw_classify (net/sched/cls_fw.c:81) Call Trace: tcf_classify (./include/net/tc_wrapper.h:197 net/sched/cls_api.c:1764 net/sched/cls_api.c:1860) tc_run (net/core/dev.c:4401) __dev_queue_xmit (net/core/dev.c:4535 net/core/dev.c:4790)
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
unaffected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | d6d5bd62a09650856e1e2010eb09853eba0d64e1 | Unavailable | None listed |
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | febf64ca79a2d6540ab6e5e197fa0f4f7e84473e | Unavailable | None listed |
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | 3d41f9a314afa94b1c7c7c75405920123220e8cd | Unavailable | None listed |
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | 18328eff2f97d1a6adcdb6d4a0f42f2f83a31e28 | Unavailable | None listed |
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | 5cf41031922c154aa5ccda8bcdb0f5e6226582ec | Unavailable | None listed |
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | 3cb055df9e8625ce699a259d8178d67b37f2b160 | Unavailable | None listed |
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | 96426c348def662b06bfdc65be3002905604927a | Unavailable | None listed |
| 1abf272022cf1d18469405f47b4ec49c6a3125db | affected | git | faeea8bbf6e958bf3c00cb08263109661975987c | Unavailable | None listed |
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
affected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 4.15 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 4.15 | Unavailable | None listed |
| 5.10.253 | unaffected | semver | Unavailable | 5.10.* | None listed |
| 5.15.203 | unaffected | semver | Unavailable | 5.15.* | None listed |
| 6.1.168 | unaffected | semver | Unavailable | 6.1.* | None listed |
| 6.6.134 | unaffected | semver | Unavailable | 6.6.* | None listed |
| 6.12.81 | unaffected | semver | Unavailable | 6.12.* | None listed |
| 6.18.22 | unaffected | semver | Unavailable | 6.18.* | None listed |
| 6.19.12 | unaffected | semver | Unavailable | 6.19.* | None listed |
| 7.0 | unaffected | original_commit_for_fix | Unavailable | * | None listed |