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<title>user/sven/linux.git/kernel/uid16.c, branch v4.9.272</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2018-01-10T08:29:52Z</updated>
<entry>
<title>kernel: make groups_sort calling a responsibility group_info allocators</title>
<updated>2018-01-10T08:29:52Z</updated>
<author>
<name>Thiago Rafael Becker</name>
<email>thiago.becker@gmail.com</email>
</author>
<published>2017-12-14T23:33:12Z</published>
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<id>urn:sha1:79258d9834803518a80b0ed0603c790638f0478b</id>
<content type='text'>
commit bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758 upstream.

In testing, we found that nfsd threads may call set_groups in parallel
for the same entry cached in auth.unix.gid, racing in the call of
groups_sort, corrupting the groups for that entry and leading to
permission denials for the client.

This patch:
 - Make groups_sort globally visible.
 - Move the call to groups_sort to the modifiers of group_info
 - Remove the call to groups_sort from set_groups

Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com
Signed-off-by: Thiago Rafael Becker &lt;thiago.becker@gmail.com&gt;
Reviewed-by: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Reviewed-by: NeilBrown &lt;neilb@suse.com&gt;
Acked-by: "J. Bruce Fields" &lt;bfields@fieldses.org&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</content>
</entry>
<entry>
<title>cred: simpler, 1D supplementary groups</title>
<updated>2016-10-08T01:46:30Z</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2016-10-08T00:03:12Z</published>
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<id>urn:sha1:81243eacfa400f5f7b89f4c2323d0de9982bb0fb</id>
<content type='text'>
Current supplementary groups code can massively overallocate memory and
is implemented in a way so that access to individual gid is done via 2D
array.

If number of gids is &lt;= 32, memory allocation is more or less tolerable
(140/148 bytes).  But if it is not, code allocates full page (!)
regardless and, what's even more fun, doesn't reuse small 32-entry
array.

2D array means dependent shifts, loads and LEAs without possibility to
optimize them (gid is never known at compile time).

All of the above is unnecessary.  Switch to the usual
trailing-zero-len-array scheme.  Memory is allocated with
kmalloc/vmalloc() and only as much as needed.  Accesses become simpler
(LEA 8(gi,idx,4) or even without displacement).

Maximum number of gids is 65536 which translates to 256KB+8 bytes.  I
think kernel can handle such allocation.

On my usual desktop system with whole 9 (nine) aux groups, struct
group_info shrinks from 148 bytes to 44 bytes, yay!

Nice side effects:

 - "gi-&gt;gid[i]" is shorter than "GROUP_AT(gi, i)", less typing,

 - fix little mess in net/ipv4/ping.c
   should have been using GROUP_AT macro but this point becomes moot,

 - aux group allocation is persistent and should be accounted as such.

Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by
Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Cc: Vasily Kulikov &lt;segoon@openwall.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>groups: Consolidate the setgroups permission checks</title>
<updated>2014-12-05T23:19:27Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2014-12-05T23:19:27Z</published>
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<id>urn:sha1:7ff4d90b4c24a03666f296c3d4878cd39001e81e</id>
<content type='text'>
Today there are 3 instances of setgroups and due to an oversight their
permission checking has diverged.  Add a common function so that
they may all share the same permission checking code.

This corrects the current oversight in the current permission checks
and adds a helper to avoid this in the future.

A user namespace security fix will update this new helper, shortly.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</content>
</entry>
<entry>
<title>userns:  Kill nsown_capable it makes the wrong thing easy</title>
<updated>2013-08-31T06:44:11Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2013-03-20T19:49:49Z</published>
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<id>urn:sha1:c7b96acf1456ef127fef461fcfedb54b81fecfbb</id>
<content type='text'>
nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and
CAP_SETGID.  For the existing users it doesn't noticably simplify things and
from the suggested patches I have seen it encourages people to do the wrong
thing.  So remove nsown_capable.

Acked-by: Serge Hallyn &lt;serge.hallyn@canonical.com&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</content>
</entry>
<entry>
<title>make SYSCALL_DEFINE&lt;n&gt;-generated wrappers do asmlinkage_protect</title>
<updated>2013-03-04T03:58:33Z</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2013-01-21T20:25:54Z</published>
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<id>urn:sha1:2cf0966683430b6468f36ca20515a33ca7f2403c</id>
<content type='text'>
... and switch i386 to HAVE_SYSCALL_WRAPPERS, killing open-coded
uses of asmlinkage_protect() in a bunch of syscalls.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>userns: Convert setting and getting uid and gid system calls to use kuid and kgid</title>
<updated>2012-05-03T10:28:41Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2012-02-08T02:51:01Z</published>
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<id>urn:sha1:a29c33f4e506e1dae7e0985b6328046535becbf8</id>
<content type='text'>
Convert setregid, setgid, setreuid, setuid,
setresuid, getresuid, setresgid, getresgid, setfsuid, setfsgid,
getuid, geteuid, getgid, getegid,
waitpid, waitid, wait4.

Convert userspace uids and gids into kuids and kgids before
being placed on struct cred.  Convert struct cred kuids and
kgids into userspace uids and gids when returning them.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
</content>
</entry>
<entry>
<title>userns: Convert group_info values from gid_t to kgid_t.</title>
<updated>2012-05-03T10:27:21Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2011-11-14T23:56:38Z</published>
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<id>urn:sha1:ae2975bc3476243b45a1e2344236d7920c268f38</id>
<content type='text'>
As a first step to converting struct cred to be all kuid_t and kgid_t
values convert the group values stored in group_info to always be
kgid_t values.   Unless user namespaces are used this change should
have no effect.

Acked-by: Serge Hallyn &lt;serge.hallyn@canonical.com&gt;
Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
</content>
</entry>
<entry>
<title>userns: user namespaces: convert several capable() calls</title>
<updated>2011-03-24T02:47:08Z</updated>
<author>
<name>Serge E. Hallyn</name>
<email>serge@hallyn.com</email>
</author>
<published>2011-03-23T23:43:24Z</published>
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<id>urn:sha1:b0e77598f87107001a00b8a4ece9c95e4254ccc4</id>
<content type='text'>
CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(),
because the resource comes from current's own ipc namespace.

setuid/setgid are to uids in own namespace, so again checks can be against
current_user_ns().

Changelog:
	Jan 11: Use task_ns_capable() in place of sched_capable().
	Jan 11: Use nsown_capable() as suggested by Bastian Blank.
	Jan 11: Clarify (hopefully) some logic in futex and sched.c
	Feb 15: use ns_capable for ipc, not nsown_capable
	Feb 23: let copy_ipcs handle setting ipc_ns-&gt;user_ns
	Feb 23: pass ns down rather than taking it from current

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Serge E. Hallyn &lt;serge.hallyn@canonical.com&gt;
Acked-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@free.fr&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>headers: utsname.h redux</title>
<updated>2009-09-24T01:13:10Z</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2009-09-24T00:22:25Z</published>
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<id>urn:sha1:2bcd57ab61e7cabed626226a3771617981c11ce1</id>
<content type='text'>
* remove asm/atomic.h inclusion from linux/utsname.h --
   not needed after kref conversion
 * remove linux/utsname.h inclusion from files which do not need it

NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>[CVE-2009-0029] System call wrappers part 19</title>
<updated>2009-01-14T13:15:26Z</updated>
<author>
<name>Heiko Carstens</name>
<email>heiko.carstens@de.ibm.com</email>
</author>
<published>2009-01-14T13:14:21Z</published>
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<id>urn:sha1:003d7ab479168132a2b2c6700fe682b08f08ab0c</id>
<content type='text'>
Signed-off-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
</content>
</entry>
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