From: Dmitry V. Levin <ldv@altlinux.org>
Date: Sat, 26 Dec 2015 23:13:27 +0000 (+0300)
Subject: sparc64: fix incorrect sign extension in sys_sparc64_personality
X-Git-Tag: v3.2.77~39
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f2ed5d5f58037e83b57a6dab9738a207eb75d96;p=pandora-kernel.git

sparc64: fix incorrect sign extension in sys_sparc64_personality

commit 525fd5a94e1be0776fa652df5c687697db508c91 upstream.

The value returned by sys_personality has type "long int".
It is saved to a variable of type "int", which is not a problem
yet because the type of task_struct->pesonality is "unsigned int".
The problem is the sign extension from "int" to "long int"
that happens on return from sys_sparc64_personality.

For example, a userspace call personality((unsigned) -EINVAL) will
result to any subsequent personality call, including absolutely
harmless read-only personality(0xffffffff) call, failing with
errno set to EINVAL.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

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