Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 4b6798024f7b2d535f3db1002c760143cdbd1bd3; affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 3c54b66c83fb8fcbde8e6a7bf90b65856e39f827; affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 5a6b15f861b7c1304949e3350d23490a5fe429fd; affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 6c7fbdb8ffde6413640de7cfbd7c976c353e89f8; affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 8027964931785cb73d520ac70a342a3dc16c249b; affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 414726b69921fe6355ae453f5b35e68dd078342a; affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 572ce62778519a7d4d1c15f55dd2e45a474133c4; affected d3aedd5ebd4b0b925b0bcda548066803e1318499 before 9ca562bb8e66978b53028fa32b1a190708e6a091 |
| Linux / Linux | affected 3.9; unaffected 0 before 3.9; unaffected 5.10.253 through 5.10.*; unaffected 5.15.203 through 5.15.*; unaffected 6.1.168 through 6.1.*; unaffected 6.6.134 through 6.6.*; unaffected 6.12.81 through 6.12.*; unaffected 6.18.22 through 6.18.*; unaffected 6.19.12 through 6.19.*; unaffected 7.0 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/4b6798024f7b2d535f3db1002c760143cdbd1bd3
- https://git.kernel.org/stable/c/3c54b66c83fb8fcbde8e6a7bf90b65856e39f827
- https://git.kernel.org/stable/c/5a6b15f861b7c1304949e3350d23490a5fe429fd
- https://git.kernel.org/stable/c/6c7fbdb8ffde6413640de7cfbd7c976c353e89f8
- https://git.kernel.org/stable/c/8027964931785cb73d520ac70a342a3dc16c249b
- https://git.kernel.org/stable/c/414726b69921fe6355ae453f5b35e68dd078342a
- https://git.kernel.org/stable/c/572ce62778519a7d4d1c15f55dd2e45a474133c4
- https://git.kernel.org/stable/c/9ca562bb8e66978b53028fa32b1a190708e6a091
ADP enrichment
No English description supplied.
No English description supplied.
No references supplied.