| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 62/80] sparc64: fix incorrect sign extension in sys_sparc64_personality | Date | Tue, 1 Mar 2016 15:45:56 -0800 |
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3.10-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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/sparc/kernel/sys_sparc_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -416,7 +416,7 @@ out: SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality) { - int ret; + long ret; if (personality(current->personality) == PER_LINUX32 && personality(personality) == PER_LINUX)
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