[3.11.y.z extended stable] Patch "s390/bpf, jit: initialize A register if 1st insn is BPF_S_LDX_B_MSH" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Wed May 7 11:08:52 UTC 2014

This is a note to let you know that I have just added a patch titled

    s390/bpf,jit: initialize A register if 1st insn is BPF_S_LDX_B_MSH

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see



>From 390e690c940755b1bed255b41983dd662a3f911f Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky at de.ibm.com>
Date: Fri, 25 Apr 2014 10:53:44 +0200
Subject: s390/bpf,jit: initialize A register if 1st insn is BPF_S_LDX_B_MSH

commit 6e0de817594c61f3b392a9245deeb09609ec707d upstream.

The A register needs to be initialized to zero in the prolog if the
first instruction of the BPF program is BPF_S_LDX_B_MSH to prevent
leaking the content of %r5 to user space.

Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
 arch/s390/net/bpf_jit_comp.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 3d613b8..8ccd6a6 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -276,7 +276,6 @@ static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter)
 	case BPF_S_LD_W_IND:
 	case BPF_S_LD_H_IND:
 	case BPF_S_LD_B_IND:
-	case BPF_S_LDX_B_MSH:
 	case BPF_S_LD_IMM:
 	case BPF_S_LD_MEM:
 	case BPF_S_MISC_TXA:

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