From: Dmitry V. Levin Date: Sat, 26 Dec 2015 23:13:27 +0000 (+0300) Subject: sparc64: fix incorrect sign extension in sys_sparc64_personality X-Git-Tag: v4.1.18~139 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5301c0647782e71150361a3854ccf3e004b79bb9;p=platform%2Fkernel%2Flinux-exynos.git sparc64: fix incorrect sign extension in sys_sparc64_personality [ Upstream commit 525fd5a94e1be0776fa652df5c687697db508c91 ] 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 Cc: Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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)