Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 076/136] sparc64: fix incorrect sign extension in sys_sparc64_personality | Date | Tue, 2 Feb 2016 10:14:31 -0800 |
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3.13.11-ckt34 -stable review patch. If anyone has any objections, please let me know.
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From: "Dmitry V. Levin" <ldv@altlinux.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@altlinux.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kamal Mostafa <kamal@canonical.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 25db14a..47ae8d7 100644 --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -412,7 +412,7 @@ 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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