CVE-2026-31680

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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

History

14 Jul 2026, 13:18

Type Values Removed Values Added
References
  • () https://cert-portal.siemens.com/productcert/html/ssa-019113.html -
  • () https://cert-portal.siemens.com/productcert/html/ssa-082556.html -

06 May 2026, 21:23

Type Values Removed Values Added
CPE cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
CWE NVD-CWE-noinfo
First Time Linux
Linux linux Kernel
References () https://git.kernel.org/stable/c/3c54b66c83fb8fcbde8e6a7bf90b65856e39f827 - () https://git.kernel.org/stable/c/3c54b66c83fb8fcbde8e6a7bf90b65856e39f827 - Patch
References () https://git.kernel.org/stable/c/414726b69921fe6355ae453f5b35e68dd078342a - () https://git.kernel.org/stable/c/414726b69921fe6355ae453f5b35e68dd078342a - Patch
References () https://git.kernel.org/stable/c/4b6798024f7b2d535f3db1002c760143cdbd1bd3 - () https://git.kernel.org/stable/c/4b6798024f7b2d535f3db1002c760143cdbd1bd3 - Patch
References () https://git.kernel.org/stable/c/572ce62778519a7d4d1c15f55dd2e45a474133c4 - () https://git.kernel.org/stable/c/572ce62778519a7d4d1c15f55dd2e45a474133c4 - Patch
References () https://git.kernel.org/stable/c/5a6b15f861b7c1304949e3350d23490a5fe429fd - () https://git.kernel.org/stable/c/5a6b15f861b7c1304949e3350d23490a5fe429fd - Patch
References () https://git.kernel.org/stable/c/6c7fbdb8ffde6413640de7cfbd7c976c353e89f8 - () https://git.kernel.org/stable/c/6c7fbdb8ffde6413640de7cfbd7c976c353e89f8 - Patch
References () https://git.kernel.org/stable/c/8027964931785cb73d520ac70a342a3dc16c249b - () https://git.kernel.org/stable/c/8027964931785cb73d520ac70a342a3dc16c249b - Patch
References () https://git.kernel.org/stable/c/9ca562bb8e66978b53028fa32b1a190708e6a091 - () https://git.kernel.org/stable/c/9ca562bb8e66978b53028fa32b1a190708e6a091 - Patch

27 Apr 2026, 15:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

25 Apr 2026, 09:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-04-25 09:16

Updated : 2026-07-14 13:18


NVD link : CVE-2026-31680

Mitre link : CVE-2026-31680

CVE.ORG link : CVE-2026-31680


JSON object : View

Products Affected

linux

  • linux_kernel