CVE-2026-31680
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: ipv6: flowlabel: defer exclusive option free until RCU teardown
In the Linux kernel, the following vulnerability has been resolved: net: ipv6: flowlabel: defer exclusive option free until RCU teardown `ip6fl_seq_show()` walks the global flowlabel hash under the seq-file RCU read-side lock and prints `fl->opt->opt_nflen` when an option block is present. Exclusive flowlabels currently free `fl->opt` as soon as `fl->users` drops to zero in `fl_release()`. However, the surrounding `struct ip6_flowlabel` remains visible in the global hash table until later garbage collection removes it and `fl_free_rcu()` finally tears it down. A concurrent `/proc/net/ip6_flowlabel` reader can therefore race that early `kfree()` and dereference freed option state, triggering a crash in `ip6fl_seq_show()`. Fix this by keeping `fl->opt` alive until `fl_free_rcu()`. That matches the lifetime already required for the enclosing flowlabel while readers can still reach it under RCU.
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) |
|---|---|---|---|---|---|
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 4b6798024f7b2d535f3db1002c760143cdbd1bd3 | Unavailable | None listed |
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 3c54b66c83fb8fcbde8e6a7bf90b65856e39f827 | Unavailable | None listed |
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 5a6b15f861b7c1304949e3350d23490a5fe429fd | Unavailable | None listed |
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 6c7fbdb8ffde6413640de7cfbd7c976c353e89f8 | Unavailable | None listed |
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 8027964931785cb73d520ac70a342a3dc16c249b | Unavailable | None listed |
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 414726b69921fe6355ae453f5b35e68dd078342a | Unavailable | None listed |
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 572ce62778519a7d4d1c15f55dd2e45a474133c4 | Unavailable | None listed |
| d3aedd5ebd4b0b925b0bcda548066803e1318499 | affected | git | 9ca562bb8e66978b53028fa32b1a190708e6a091 | 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) |
|---|---|---|---|---|---|
| 3.9 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 3.9 | 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 |