CVE-2026-98629

Source
https://cve.org/CVERecord?id=CVE-2026-98629
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98629.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-98629
Downstream
Published
2026-10-18T15:19:50Z
Modified
2026-10-19T02:46:58Z
Summary
net/sched: cls_u32: fix manual hash table handle IDR aliasing
Details

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

net/sched: cls_u32: fix manual hash table handle IDR aliasing

A u32 hash table created with an explicit handle ('tc filter add ... handle 801: u32 divisor N') keys its IDR entry on the raw handle, while the destroy paths free it under handle2id(handle). The two key domains disagree for handles in the 0x800..0xFFF htid range: handle2id() folds them back into the auto-allocated id space (1..0x7FF).

A manual table therefore leaves its raw-keyed IDR entry unreachable on delete (a permanent leak), and its delete can drop the idr entry of an unrelated live auto table. A later auto allocation can then hand out a handle that aliases the live manual table; u32_lookup_ht() first-match routes lookups and TCA_U32_LINK for that htid to the wrong table.

Key the divisor-path alloc on handle2id(handle) so allocation and removal share one key domain. A manual handle that maps onto an id already in use is rejected with -ENOSPC, and auto allocation skips ids held by live manual tables.

Conditions to recreate: ip link add test0 type dummy tc qdisc add dev test0 clsact tc filter add dev test0 ingress protocol ip pref 1
handle 801: u32 divisor 16 tc filter add dev test0 ingress protocol ip pref 2 u32 divisor 16 tc -d filter show dev test0 ingress | grep 'fh 801:'

unpatched: two live tables with handle 0x80100000 (the pref 2 root

hnode is auto-allocated id 1); patched: the auto hnode takes id 2.

Also tested with a poc with a live u32 table on the block, add/delete a manual table 'handle 901: u32 divisor 1' twice; unpatched, the re-add fails with -ENOSPC because the raw key leaked on the first delete.

Database specific
{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98629.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
9b2c3184e126b941dfa716b8128ed6db92a64e2f
Fixed
21fc07924e996e1e661268ca269c86b8d59d25b3
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
789f9963bd031c3a185605665b744912df8e7eda
Fixed
0fac292d93fdb313099e98cce928b3a524c92c94
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
73af53d82076bbe184d9ece9e14b0dc8599e6055
Fixed
54a454c5e41f5e2cb70c8163140ce095c5d5eefd
Fixed
f6696481eedfd5752b4b56eed715d0b0fe48b9c5
Fixed
2f898f9ec7c73c5697ee462681e7ea6984ee1f3d
Fixed
0a5f5d9e94dead312d32c366b917c64e552b72f7
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.1.119
Fixed
6.1.189
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.6.63
Fixed
6.6.158
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.11.10
Fixed
6.12
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4403f9293ce9ecc2a55c688d84ee37e3ba0fc1a8

Affected versions

v6.*
v6.1.119
v6.1.120
v6.1.121
v6.1.122
v6.1.123
v6.1.124
v6.1.125
v6.1.126
v6.1.127
v6.1.128
v6.1.129
v6.1.130
v6.1.131
v6.1.132
v6.1.133
v6.1.134
v6.1.135
v6.1.136
v6.1.137
v6.1.138
v6.1.139
v6.1.140
v6.1.141
v6.1.142
v6.1.143
v6.1.144
v6.1.145
v6.1.146
v6.1.147
v6.1.148
v6.1.149
v6.1.150
v6.1.151
v6.1.152
v6.1.153
v6.1.154
v6.1.155
v6.1.156
v6.1.157
v6.1.158
v6.1.159
v6.1.160
v6.1.161
v6.1.162
v6.1.163
v6.1.164
v6.1.165
v6.1.166
v6.1.167
v6.1.168
v6.1.169
v6.1.170
v6.1.171
v6.1.172
v6.1.173
v6.1.174
v6.1.175
v6.1.176
v6.1.177
v6.1.178
v6.1.179
v6.1.180
v6.1.181
v6.1.182
v6.1.183
v6.1.184
v6.1.185
v6.1.186
v6.1.187
v6.1.188
v6.11.10
v6.11.11
v6.6.100
v6.6.101
v6.6.102
v6.6.103
v6.6.104
v6.6.105
v6.6.106
v6.6.107
v6.6.108
v6.6.109
v6.6.110
v6.6.111
v6.6.112
v6.6.113
v6.6.114
v6.6.115
v6.6.116
v6.6.117
v6.6.118
v6.6.119
v6.6.120
v6.6.121
v6.6.122
v6.6.123
v6.6.124
v6.6.125
v6.6.126
v6.6.127
v6.6.128
v6.6.129
v6.6.130
v6.6.131
v6.6.132
v6.6.133
v6.6.134
v6.6.135
v6.6.136
v6.6.137
v6.6.138
v6.6.139
v6.6.140
v6.6.141
v6.6.142
v6.6.143
v6.6.144
v6.6.145
v6.6.146
v6.6.147
v6.6.148
v6.6.149
v6.6.150
v6.6.151
v6.6.152
v6.6.153
v6.6.154
v6.6.155
v6.6.156
v6.6.157
v6.6.63
v6.6.64
v6.6.65
v6.6.66
v6.6.67
v6.6.68
v6.6.69
v6.6.70
v6.6.71
v6.6.72
v6.6.73
v6.6.74
v6.6.75
v6.6.76
v6.6.77
v6.6.78
v6.6.79
v6.6.80
v6.6.81
v6.6.82
v6.6.83
v6.6.84
v6.6.85
v6.6.86
v6.6.87
v6.6.88
v6.6.89
v6.6.90
v6.6.91
v6.6.92
v6.6.93
v6.6.94
v6.6.95
v6.6.96
v6.6.97
v6.6.98
v6.6.99

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98629.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.1.189
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.158
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.112
Type
ECOSYSTEM
Events
Introduced
6.12.0
Fixed
6.18.55
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
7.2.9

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98629.json"