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Commit ec229e83 authored by Li Zefan's avatar Li Zefan Committed by Linus Torvalds
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devcgroup: fix permission check when adding entry to child cgroup 



 # cat devices.list
 c 1:3 r
 # echo 'c 1:3 w' > sub/devices.allow
 # cat sub/devices.list
 c 1:3 w

As illustrated, the parent group has no write permission to /dev/null, so
it's child should not be allowed to add this write permission.

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 17d213f8

security/device_cgroup.c

+1 −1
Original line number Diff line number Diff line
@@ -300,7 +300,7 @@ static int may_access_whitelist(struct dev_cgroup *c, 
			continue;

		if (whitem->minor != ~0 && whitem->minor != refwh->minor)

			continue;

		if (refwh->access & (~(whitem->access | ACC_MASK)))

		if (refwh->access & (~whitem->access))

			continue;

		return 1;

	}