From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46394 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754277AbdHYApR (ORCPT ); Thu, 24 Aug 2017 20:45:17 -0400 Subject: Patch "bpf/verifier: fix min/max handling in BPF_SUB" has been added to the 4.12-stable tree To: ecree@solarflare.com, daniel@iogearbox.net, davem@davemloft.net, gregkh@linuxfoundation.org Cc: , From: Date: Thu, 24 Aug 2017 17:44:35 -0700 Message-ID: <150362187513396@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 bpf/verifier: fix min/max handling in BPF_SUB to the 4.12-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-verifier-fix-min-max-handling-in-bpf_sub.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Thu Aug 24 17:43:45 PDT 2017 From: Edward Cree Date: Fri, 21 Jul 2017 14:37:34 +0100 Subject: bpf/verifier: fix min/max handling in BPF_SUB From: Edward Cree [ Upstream commit 9305706c2e808ae59f1eb201867f82f1ddf6d7a6 ] We have to subtract the src max from the dst min, and vice-versa, since (e.g.) the smallest result comes from the largest subtrahend. Fixes: 484611357c19 ("bpf: allow access into map value arrays") Signed-off-by: Edward Cree Acked-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/verifier.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1858,10 +1858,12 @@ static void adjust_reg_min_max_vals(stru * do our normal operations to the register, we need to set the values * to the min/max since they are undefined. */ - if (min_val == BPF_REGISTER_MIN_RANGE) - dst_reg->min_value = BPF_REGISTER_MIN_RANGE; - if (max_val == BPF_REGISTER_MAX_RANGE) - dst_reg->max_value = BPF_REGISTER_MAX_RANGE; + if (opcode != BPF_SUB) { + if (min_val == BPF_REGISTER_MIN_RANGE) + dst_reg->min_value = BPF_REGISTER_MIN_RANGE; + if (max_val == BPF_REGISTER_MAX_RANGE) + dst_reg->max_value = BPF_REGISTER_MAX_RANGE; + } switch (opcode) { case BPF_ADD: @@ -1872,10 +1874,17 @@ static void adjust_reg_min_max_vals(stru dst_reg->min_align = min(src_align, dst_align); break; case BPF_SUB: + /* If one of our values was at the end of our ranges, then the + * _opposite_ value in the dst_reg goes to the end of our range. + */ + if (min_val == BPF_REGISTER_MIN_RANGE) + dst_reg->max_value = BPF_REGISTER_MAX_RANGE; + if (max_val == BPF_REGISTER_MAX_RANGE) + dst_reg->min_value = BPF_REGISTER_MIN_RANGE; if (dst_reg->min_value != BPF_REGISTER_MIN_RANGE) - dst_reg->min_value -= min_val; + dst_reg->min_value -= max_val; if (dst_reg->max_value != BPF_REGISTER_MAX_RANGE) - dst_reg->max_value -= max_val; + dst_reg->max_value -= min_val; dst_reg->min_align = min(src_align, dst_align); break; case BPF_MUL: Patches currently in stable-queue which might be from ecree@solarflare.com are queue-4.12/bpf-fix-mixed-signed-unsigned-derived-min-max-value-bounds.patch queue-4.12/bpf-verifier-fix-min-max-handling-in-bpf_sub.patch