oss-sec mailing list archives
CVE request: Linux kernel mbcache lock contention denial of service.
From: Wade Mealing <wmealing () redhat com>
Date: Mon, 22 Aug 2016 15:28:51 +1000
Gday, A design flaw was found in the file extended attribute handling of the linux kernels handling of cached attributes. Too many entries in the cache cause a soft lockup while attempting to iterate the cache and access relevant locks. Upstream has replaced the mbcache code with an updated version which was not a patch but a clear-cut reimplementation of the code, no single diff Soft lockup information is in both the bugzilla.kernel.org and referred to in the LWN article. This would affect containers running with ext4 as it shares the same mbcache between all containers/host. This did not affect Red Hat Enterprise Linux versions 5,6 or 7, so I can't validate the claim that it does affect other newer kernels. This may be worthwhile tracking for others who are affected by this flaw. For those following along at home, this seemed to be fixed in: ± git tag --contains be0726d33cb8f411945884664924bed3cb8c70ee v4.6 However I can't be sure which factor introduced the issue, but I've been unable to reproduce with the given instructions. Thanks, Wade Mealing Red Hat Product Security Upstream discussion: https://lwn.net/Articles/668718/ Bugzilla kernel submission: https://bugzilla.kernel.org/show_bug.cgi?id=107301 Red Hat Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1360968
Current thread:
- CVE request: Linux kernel mbcache lock contention denial of service. Wade Mealing (Aug 21)
- Re: CVE request: Linux kernel mbcache lock contention denial of service. cve-assign (Aug 25)
- Re: CVE request: Linux kernel mbcache lock contention denial of service. Greg KH (Sep 05)
- Re: CVE request: Linux kernel mbcache lock contention denial of service. Andreas Stieger (Sep 06)