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 70E98C4332F for ; Mon, 9 May 2022 15:00:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237863AbiEIPD7 (ORCPT ); Mon, 9 May 2022 11:03:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237817AbiEIPD4 (ORCPT ); Mon, 9 May 2022 11:03:56 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53D422C96D7 for ; Mon, 9 May 2022 07:59:54 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id d17so14123095plg.0 for ; Mon, 09 May 2022 07:59:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=zVLvc36s8wFy0NwwyUQY9+GAzhoxm6ANmW5t5SeS4wc=; b=lL109MqdgpeKUJKTzJme+MShTxpF/zVho7YdlzRI0evfUnaB6lEse1tOtQTjS1Tc+1 8eS+fvHwpyXPUjVXohx8hHOQC2QAW2O0j/43NLUBKH3TmXcD3m6rslYcOGX5yWphvM6K S8ISGa5UuXL/RJ8hQaLUwwYha/LshcaxHJLAzT61ae/p2/Hv1IRwJSBH0dE+i0dWrLxJ XFc6YuOjB/NQ2bLC6qbPIKyvBpjT7nib4SVITU3PIMD8rVdt7ECeMz1fgZa6QCH6WusN hQzb6Q9CXg61+1p4uYdq9FpZ/h633SZRU0GdGFsCgclNY6izDszV7FxnbiEXOiNzIM3V lsiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=zVLvc36s8wFy0NwwyUQY9+GAzhoxm6ANmW5t5SeS4wc=; b=iSYmAyVjm85fX+wqzOZdWkpCg2dGlTqxil4W0CAFxAXWtZ8tRpmV/GF4r4pn9dukbM kh7p5Q9KoTuBzWZYiVvuGEGKq5xN2gP3GdjhcAp6zqMoff37uPztUmW112EdEC3B/tDk e96xPHH47HT4DPShKeK/rrgJLpdpoTNZ8F0hpWVib2aC3MZBP6JMv3igpLji/sfo7fho iSnTdBeKjSttH14z35vJzMDV9cD0IrLc7ax/oE7kiomPwSGt8WqjEmgpWwHDuZKUyrEq P9wRPMsMWF5HrMSampMYLtfWD/URxav5bUb28Udxo04UmPKkMH0jS8Nnse3nPPscfUrr 8DbA== X-Gm-Message-State: AOAM533PTtZA9MaXH1etAu3QYQ5DWI8n+9rGyn+a70rtV1p2IWTzw1++ k3/YgiYMke5c2fsQS5U6sOw= X-Google-Smtp-Source: ABdhPJyioPNRcbngaf3SWmm7/A2zW3bmZ3CORM2h7zud6vyHvSXxQeZNu8Qnc8O6rpE/HOYY9xelSA== X-Received: by 2002:a17:902:8501:b0:15f:173:40e1 with SMTP id bj1-20020a170902850100b0015f017340e1mr9313015plb.74.1652108393048; Mon, 09 May 2022 07:59:53 -0700 (PDT) Received: from edumazet1.svl.corp.google.com ([2620:15c:2c4:201:3495:a425:2eb9:fac3]) by smtp.gmail.com with ESMTPSA id h189-20020a636cc6000000b003c18ab7389asm8068977pgc.36.2022.05.09.07.59.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 May 2022 07:59:52 -0700 (PDT) From: Eric Dumazet To: Andrew Morton Cc: linux-kernel , linux-mm , Eric Dumazet , Eric Dumazet , syzbot , Waiman Long Subject: [PATCH] mm/page_owner: use strscpy() instead of strlcpy() Date: Mon, 9 May 2022 07:59:49 -0700 Message-Id: <20220509145949.265184-1-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.36.0.512.ge40c2bad7a-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- mm/page_owner.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index fb3a05fdebdbf1c3646ba1584cbf06facf0e7a9a..19bc559e49040e60c03a5f4268c89618fa0f1b1c 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -168,7 +168,7 @@ static inline void __set_page_owner_handle(struct page_ext *page_ext, page_owner->pid = current->pid; page_owner->tgid = current->tgid; page_owner->ts_nsec = local_clock(); - strlcpy(page_owner->comm, current->comm, + strscpy(page_owner->comm, current->comm, sizeof(page_owner->comm)); __set_bit(PAGE_EXT_OWNER, &page_ext->flags); __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); -- 2.36.0.512.ge40c2bad7a-goog