From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B731EC433EF for ; Mon, 9 May 2022 15:52:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238751AbiEIP4b (ORCPT ); Mon, 9 May 2022 11:56:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238754AbiEIP4H (ORCPT ); Mon, 9 May 2022 11:56:07 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1AA3E1C5E28 for ; Mon, 9 May 2022 08:52:13 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id d22-20020a25add6000000b00645d796034fso12384516ybe.2 for ; Mon, 09 May 2022 08:52:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=EthTtQDUrpipFQD0rJkKc9pv5XwzIQQETVz7McYZec8=; b=F4CoU8RsUWJt8MVDcuBdI5IyacBfsKkDmbyWBR5agiSrMiC/IVNzjZ6qBTm/mZ40aJ fq6Lpqp2jeogdEk8rH0PfMrAj6vMm+UfwSwelQwmZ3voD8UXZZ9oQ3jpn/h8wsQWXpMc OaxlfEGCVT88Lr2Idc3VrEcdjunkpAR53p0kE7fvnswo3paZtL/kINTLJDzXYwMdiIj2 dSMGI7Ye9u0juN3ppXUfZd9g8NvgEaobKX9WEvLcu6vBivbGlvon9AUpRNmrcOmc3JZX CLSA+iBP/8GUKFzVkCfuWNFl8HPc2vM8GSE2V6/Uy7gL0+M1lQeXiC486Wtjxr+SIhx0 mCcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=EthTtQDUrpipFQD0rJkKc9pv5XwzIQQETVz7McYZec8=; b=hlcegoII70f9/xLv+EhjaRl/kjjdnrHtj+a059edPJG0nFHDlcitv1x8mPa5t3TLWC WdqFvL4hfNm/erxhEKlooEbr/SnbU+r1fIpDj5jK6yfL3+By3FlDU1FSdXHb/+gIdh5k 2eRZKVP7ffMjCV18lMQqyzqVaesLppezqLfXftAkDmKxN2osKcnw8LeJhJ4hyvvflVR3 CQSgGvg5Kimb7NpDbg6s/USi+KaN98a17uhjuJHJYiu1Cockvq280HPfg5U2mF5UTpwt zj+7WRJCASQ7ap/2slVv92p7n8UPUOjuwyXeY7rNTLz++1mbZH8mayHS3VawVPi/7XNe o5Ew== X-Gm-Message-State: AOAM531unTKLeVoJXYrE3A4nZF+qzxUKkNvDmS+PL8oBDDy0oXo1muOR ZYhAvSYc8IWfcMloRzKxWxshi2AogK+nNA== X-Google-Smtp-Source: ABdhPJwMSobU5lLkP9gFyup+2NqUl4oDxUipxzjeiKvjpxFz3dmc9pf3/U7cmesVAWBdnF3PlNijKQW2UZlbuA== X-Received: from shakeelb.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:28b]) (user=shakeelb job=sendgmr) by 2002:a25:5085:0:b0:648:efed:a38a with SMTP id e127-20020a255085000000b00648efeda38amr12991226ybb.208.1652111532350; Mon, 09 May 2022 08:52:12 -0700 (PDT) Date: Mon, 9 May 2022 15:52:09 +0000 In-Reply-To: <20220509145949.265184-1-eric.dumazet@gmail.com> Message-Id: <20220509155209.5gilgrvntpt5vlf5@google.com> Mime-Version: 1.0 References: <20220509145949.265184-1-eric.dumazet@gmail.com> Subject: Re: [PATCH] mm/page_owner: use strscpy() instead of strlcpy() From: Shakeel Butt To: Eric Dumazet Cc: Andrew Morton , linux-kernel , linux-mm , Eric Dumazet , syzbot , Waiman Long Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 09, 2022 at 07:59:49AM -0700, Eric Dumazet wrote: > From: Eric Dumazet > > current->comm[] is not a string (no guarantee for > a zero byte in it). > > strlcpy(s1, s2, l) is calling strlen(s2), potentially > causing out-of-bound access, as reported by syzbot: > > detected buffer overflow in __fortify_strlen > ------------[ cut here ]------------ > kernel BUG at lib/string_helpers.c:980! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 4087 Comm: dhcpcd-run-hooks Not tainted 5.18.0-rc3-syzkaller-01537-g20b87e7c29df #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:fortify_panic+0x18/0x1a lib/string_helpers.c:980 > Code: 8c e8 c5 ba e1 fa e9 23 0f bf fa e8 0b 5d 8c f8 eb db 55 48 89 fd e8 e0 49 40 f8 48 89 ee 48 c7 c7 80 f5 26 8a e8 99 09 f1 ff <0f> 0b e8 ca 49 40 f8 48 8b 54 24 18 4c 89 f1 48 c7 c7 00 00 27 8a > RSP: 0018:ffffc900000074a8 EFLAGS: 00010286 > > RAX: 000000000000002c RBX: ffff88801226b728 RCX: 0000000000000000 > RDX: ffff8880198e0000 RSI: ffffffff81600458 RDI: fffff52000000e87 > RBP: ffffffff89da2aa0 R08: 000000000000002c R09: 0000000000000000 > R10: ffffffff815fae2e R11: 0000000000000000 R12: ffff88801226b700 > R13: ffff8880198e0830 R14: 0000000000000000 R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f5876ad6ff8 CR3: 000000001a48c000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 > Call Trace: > > __fortify_strlen include/linux/fortify-string.h:128 [inline] > strlcpy include/linux/fortify-string.h:143 [inline] > __set_page_owner_handle+0x2b1/0x3e0 mm/page_owner.c:171 > __set_page_owner+0x3e/0x50 mm/page_owner.c:190 > prep_new_page mm/page_alloc.c:2441 [inline] > get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 > __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 > alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 > alloc_slab_page mm/slub.c:1799 [inline] > allocate_slab+0x26c/0x3c0 mm/slub.c:1944 > new_slab mm/slub.c:2004 [inline] > ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 > __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 > slab_alloc_node mm/slub.c:3183 [inline] > slab_alloc mm/slub.c:3225 [inline] > __kmem_cache_alloc_lru mm/slub.c:3232 [inline] > kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3242 > dst_alloc+0x146/0x1f0 net/core/dst.c:92 > > Fixes: 865ed6a32786 ("mm/page_owner: record task command name") > Signed-off-by: Eric Dumazet > Reported-by: syzbot > Cc: Waiman Long Acked-by: Shakeel Butt