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: firefly_0821_release~176^2~475^2~257 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a0b1c2d0f53c8368eef4018ed7ce15b6c015aa77;p=firefly-linux-kernel-4.4.55.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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c index 30e7ddb27a3a..c690c8e16a96 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)