kernel 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: Paul Vaduva <Paul.Vaduva@enea.com>

2 files changed, 29 insertions, 0 deletions

diff --git a/recipes-kernel/linux/files/Trusty-SRU-ipc-fix-compat-msgrcv-with-negative-msgtyp.patch b/recipes-kernel/linux/files/Trusty-SRU-ipc-fix-compat-msgrcv-with-negative-msgtyp.patch
new file mode 100644
index 0000000..b90a114
--- /dev/null
+++ b/recipes-kernel/linux/files/Trusty-SRU-ipc-fix-compat-msgrcv-with-negative-msgtyp.patch
@@ -0,0 +1,27 @@
+BugLink: http://bugs.launchpad.net/bugs/1393355
+
+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 <mguzik@redhat.com>
+Reported-by: Gabriellla Schmidt <gsc@bruker.de>
+
+Upstream-Status::Backport
+Kernel 3.14
+
+diff --git a/ipc/compat.c b/ipc/compat.c
+index 892f658..d3b3760 100644
+--- 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:
diff --git a/recipes-kernel/linux/linux-qoriq_3.12.bbappend b/recipes-kernel/linux/linux-qoriq_3.12.bbappend
index f9311e9..bd21278 100644
--- a/recipes-kernel/linux/linux-qoriq_3.12.bbappend
+++ b/recipes-kernel/linux/linux-qoriq_3.12.bbappend
@@ -1 +1,3 @@
 require recipes-kernel/linux/linux-qoriq-common.inc
+SRC_URI += "file://Trusty-SRU-ipc-fix-compat-msgrcv-with-negative-msgtyp.patch \
+            "