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Message-Id: <1454030348-17736-110-git-send-email-kamal@canonical.com>
Date: Thu, 28 Jan 2016 17:17:27 -0800
From: Kamal Mostafa <kamal@...onical.com>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org,
kernel-team@...ts.ubuntu.com
Cc: "Dmitry V. Levin" <ldv@...linux.org>,
"David S. Miller" <davem@...emloft.net>,
Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.19.y-ckt 109/210] sparc64: fix incorrect sign extension in sys_sparc64_personality
3.19.8-ckt14 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
From: "Dmitry V. Levin" <ldv@...linux.org>
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@...linux.org>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
arch/sparc/kernel/sys_sparc_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index 30e7ddb..c690c8e 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -413,7 +413,7 @@ out:
SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
{
- int ret;
+ long ret;
if (personality(current->personality) == PER_LINUX32 &&
personality(personality) == PER_LINUX)
--
1.9.1
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