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: v3.12.56~26 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a6827009cb013e8cffb430e960f656d6c6b9d60e;p=linux 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 Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c index d188c591f2d6..608f9390396e 100644 --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -411,7 +411,7 @@ out: SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality) { - int ret; + long ret; if (personality(current->personality) == PER_LINUX32 && personality(personality) == PER_LINUX)