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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EAF3C433EF for ; Mon, 9 May 2022 15:52:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 127C66B0074; Mon, 9 May 2022 11:52:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0D7726B0075; Mon, 9 May 2022 11:52:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EBA148D0002; Mon, 9 May 2022 11:52:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id DC13B6B0074 for ; Mon, 9 May 2022 11:52:13 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id A8F3D301D5 for ; Mon, 9 May 2022 15:52:13 +0000 (UTC) X-FDA: 79446646146.13.A80394B Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) by imf29.hostedemail.com (Postfix) with ESMTP id D72BE1200AF for ; Mon, 9 May 2022 15:52:06 +0000 (UTC) Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-2dc7bdd666fso123356967b3.7 for ; Mon, 09 May 2022 08:52:12 -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=Ix4Hmu18hj+9ZALYKhFsBrGW8eRQuijCMfGlOpC6E/ieybc4fIW4N9aTQDbdi66O15 EjYcwUlBUmpwOTYsCyyW4dz18XVYTNmtmuRxEYsgR8UcLzmdS/hn5H1Jlw2rmwm1yO7E WPJCUP676qBPc9zXtWtAosA3vOfNVCedSq4x/tq3a4wIwYsnmkZj+f6NGNiibjcrsYVE aKrcqYpwaQ8V15U8ExqLOZ5Et/bGpI7pKQgUjfFEHgEqjeJL7RlLC3vy0FQ6VUIu+UQS bFf/STSczafBoIGHSvxWsoPFEje3dRetR7KdTErXnQ1diby26gR+f0ftGIsGp8vdnwCA gYtw== X-Gm-Message-State: AOAM532hrY/soZFXt8YUzEUdj+LO373pRrV4zQEjlbNF7f97UOErG+vq VITGbd6rnw5DGyk05n3ev3LmBfTEGgeEJA== 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" X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: D72BE1200AF Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=F4CoU8Rs; spf=pass (imf29.hostedemail.com: domain of 3rDh5YggKCB0LA3D77E49HH9E7.5HFEBGNQ-FFDO35D.HK9@flex--shakeelb.bounces.google.com designates 209.85.128.201 as permitted sender) smtp.mailfrom=3rDh5YggKCB0LA3D77E49HH9E7.5HFEBGNQ-FFDO35D.HK9@flex--shakeelb.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspam-User: X-Stat-Signature: xpxjwpxnj5kn73dbrp584idnxux164wb X-HE-Tag: 1652111526-784710 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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