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Bug 832717 - kernel 5.14+ <{5.16.5,5.15.19},: use-after-free of user namespace on shm and mqueue destruction
Summary: kernel 5.14+ <{5.16.5,5.15.19},: use-after-free of user namespace on shm and ...
Status: RESOLVED FIXED
Alias: None
Product: Gentoo Security
Classification: Unclassified
Component: Kernel (show other bugs)
Hardware: All Linux
: Normal normal (vote)
Assignee: Gentoo Kernel Security
URL: https://www.openwall.com/lists/oss-se...
Whiteboard:
Keywords:
Depends on: 832716
Blocks:
  Show dependency tree
 
Reported: 2022-02-04 18:00 UTC by Michał Górny
Modified: 2022-03-26 01:42 UTC (History)
1 user (show)

See Also:
Package list:
Runtime testing required: ---

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Description Michał Górny archtester Gentoo Infrastructure gentoo-dev Security 2022-02-04 18:00:52 UTC 
From $url:

```
A use-after-free vulnerability was found in the way certain rlimit
conversions to 'ucounts' were done, affecting kernels containing merge
commit c54b245d0118 ("Merge branch 'for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace")
which is Linux v5.14 and newer.
```

According to the description, this can lead to privilege escalation if unprivileged user namespaces are enabled.

Only kernels 5.14+ are affected.  The fix is in 5.15.19 and 5.16.5.
Comment 1 Michał Górny archtester Gentoo Infrastructure gentoo-dev Security 2022-02-04 18:01:13 UTC 
Oh, and thanks to flow@ for reporting it on IRC.
Comment 2 Larry the Git Cow gentoo-dev 2022-02-04 23:51:21 UTC 
The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=8a1a81e544afce367e5430de02df365922f97128

commit 8a1a81e544afce367e5430de02df365922f97128
Author:     Mike Pagano <mpagano@gentoo.org>
AuthorDate: 2022-02-04 23:51:09 +0000
Commit:     Mike Pagano <mpagano@gentoo.org>
CommitDate: 2022-02-04 23:51:09 +0000

    sys-kernel/gentoo-sources: Autostablize for security bug per policy
    
    Remove affected kernels
    
    Bug: https://bugs.gentoo.org/832717
    Package-Manager: Portage-3.0.30, Repoman-3.0.3
    Signed-off-by: Mike Pagano <mpagano@gentoo.org>

 sys-kernel/gentoo-sources/Manifest                 | 18 --------------
 .../gentoo-sources/gentoo-sources-5.15.16.ebuild   | 28 ----------------------
 .../gentoo-sources/gentoo-sources-5.15.17.ebuild   | 28 ----------------------
 .../gentoo-sources/gentoo-sources-5.15.18.ebuild   | 28 ----------------------
 .../gentoo-sources/gentoo-sources-5.15.19.ebuild   |  2 +-
 .../gentoo-sources/gentoo-sources-5.16.2.ebuild    | 28 ----------------------
 .../gentoo-sources/gentoo-sources-5.16.3.ebuild    | 28 ----------------------
 .../gentoo-sources/gentoo-sources-5.16.4.ebuild    | 28 ----------------------
 8 files changed, 1 insertion(+), 187 deletions(-)
Comment 3 John Helmert III archtester Gentoo Infrastructure gentoo-dev Security 2022-03-26 01:42:41 UTC 
All done!