ipc: fix compat msgrcv with negative msgtyp

Compat function takes msgtyp argument as u32 and passes it down to do_msgrcv which results in casting to long, thus the sign is lost and we get a big positive number instead. Cast the argument to signed type before passing it down. Signed-off-by: Mateusz Guzik <[email protected]> Reported-by: Gabriellla Schmidt <[email protected]> Cc: Al Viro <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Manfred Spraul <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · Jan 28, 2014 · e7ca255 · e7ca255
1 parent ffa571d
commit e7ca255
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/ipc/compat.c b/ipc/compat.c
@@ -381,7 +381,7 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
 			uptr = compat_ptr(ipck.msgp);
 			fifth = ipck.msgtyp;
 		}
-		return do_msgrcv(first, uptr, second, fifth, third,
+		return do_msgrcv(first, uptr, second, (s32)fifth, third,
 				 compat_do_msg_fill);
 	}
 	case MSGGET: