From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49742 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755996AbdLVPsC (ORCPT ); Fri, 22 Dec 2017 10:48:02 -0500 Subject: Patch "[PATCH stable/4.14 04/14] bpf, ppc64: do not reload skb pointers in non-skb context" has been added to the 4.14-stable tree To: daniel@iogearbox.net, ast@kernel.org, gregkh@linuxfoundation.org, naveen.n.rao@linux.vnet.ibm.com, sandipan@linux.vnet.ibm.com Cc: , From: Date: Fri, 22 Dec 2017 16:47:47 +0100 In-Reply-To: <20171222152312.2945-5-daniel@iogearbox.net> Message-ID: <151395766712163@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled [PATCH stable/4.14 04/14] bpf, ppc64: do not reload skb pointers in non-skb context to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bpf-ppc64-do-not-reload-skb-pointers-in-non-skb-context.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Fri Dec 22 16:47:02 CET 2017 From: Daniel Borkmann Date: Fri, 22 Dec 2017 16:23:02 +0100 Subject: [PATCH stable/4.14 04/14] bpf, ppc64: do not reload skb pointers in non-skb context To: gregkh@linuxfoundation.org Cc: ast@kernel.org, daniel@iogearbox.net, jannh@google.com, stable@vger.kernel.org Message-ID: <20171222152312.2945-5-daniel@iogearbox.net> From: Daniel Borkmann [ Upstream commit 87338c8e2cbb317b5f757e6172f94e2e3799cd20 ] The assumption of unconditionally reloading skb pointers on BPF helper calls where bpf_helper_changes_pkt_data() holds true is wrong. There can be different contexts where the helper would enforce a reload such as in case of XDP. Here, we do have a struct xdp_buff instead of struct sk_buff as context, thus this will access garbage. JITs only ever need to deal with cached skb pointer reload when ld_abs/ind was seen, therefore guard the reload behind SEEN_SKB. Fixes: 156d0e290e96 ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Signed-off-by: Daniel Borkmann Reviewed-by: Naveen N. Rao Acked-by: Alexei Starovoitov Tested-by: Sandipan Das Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/net/bpf_jit_comp64.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -762,7 +762,8 @@ emit_clear: func = (u8 *) __bpf_call_base + imm; /* Save skb pointer if we need to re-cache skb data */ - if (bpf_helper_changes_pkt_data(func)) + if ((ctx->seen & SEEN_SKB) && + bpf_helper_changes_pkt_data(func)) PPC_BPF_STL(3, 1, bpf_jit_stack_local(ctx)); bpf_jit_emit_func_call(image, ctx, (u64)func); @@ -771,7 +772,8 @@ emit_clear: PPC_MR(b2p[BPF_REG_0], 3); /* refresh skb cache */ - if (bpf_helper_changes_pkt_data(func)) { + if ((ctx->seen & SEEN_SKB) && + bpf_helper_changes_pkt_data(func)) { /* reload skb pointer to r3 */ PPC_BPF_LL(3, 1, bpf_jit_stack_local(ctx)); bpf_jit_emit_skb_loads(image, ctx); Patches currently in stable-queue which might be from daniel@iogearbox.net are queue-4.14/bpf-fix-integer-overflows.patch queue-4.14/bpf-fix-branch-pruning-logic.patch queue-4.14/bpf-s390x-do-not-reload-skb-pointers-in-non-skb-context.patch queue-4.14/bpf-sparc-fix-usage-of-wrong-reg-for-load_skb_regs-after-call.patch queue-4.14/bpf-fix-incorrect-tracking-of-register-size-truncation.patch queue-4.14/bpf-don-t-prune-branches-when-a-scalar-is-replaced-with-a-pointer.patch queue-4.14/bpf-verifier-fix-bounds-calculation-on-bpf_rsh.patch queue-4.14/selftests-bpf-add-tests-for-recent-bugfixes.patch queue-4.14/bpf-fix-corruption-on-concurrent-perf_event_output-calls.patch queue-4.14/bpf-fix-incorrect-sign-extension-in-check_alu_op.patch queue-4.14/bpf-ppc64-do-not-reload-skb-pointers-in-non-skb-context.patch queue-4.14/bpf-fix-missing-error-return-in-check_stack_boundary.patch queue-4.14/bpf-force-strict-alignment-checks-for-stack-pointers.patch queue-4.14/bpf-fix-32-bit-alu-op-verification.patch queue-4.14/bpf-fix-build-issues-on-um-due-to-mising-bpf_perf_event.h.patch