From nobody Sun Apr 5 13:04:01 2026 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 85D96ECAAD8 for ; Wed, 14 Sep 2022 11:52:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229695AbiINLwX (ORCPT ); Wed, 14 Sep 2022 07:52:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229550AbiINLwU (ORCPT ); Wed, 14 Sep 2022 07:52:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75604785B7 for ; Wed, 14 Sep 2022 04:52:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E1C4261C63 for ; Wed, 14 Sep 2022 11:52:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83B40C433C1; Wed, 14 Sep 2022 11:52:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663156338; bh=4f7QnIMHb0ycvGRooXpzyLGWeV+vETSC/ILe3NrR92s=; h=From:To:Cc:Subject:Date:From; b=DBiW2GLenZPedRpYFS7qErx8A1PpUdLZ1FTTi/nBL/N0kbQuLc/x9Uxaqfvvodb5Y 8/o+uSsMfNZUZVKHyslFCBLkRr41lV8BTuN9TodiXO7a5PW5du2iYvOt4vg8tdNUiL XXhfNZqEiNeWOdjT70VoLYmAqhbiR6ZOLmAREHIpkK6XEUHKRdoTRnde/jgQ0sI9ei 9h+2qGnMcJ/MGtVFN1wVNtmPZUggTzSXtoZ+MESsPMK4ODw2AGTYa4mZtzO0eOIC7J uH1xVMk65b+Kgf7R5APtqGqo1c5VRNLQiMSJ3aLW7EKz1eAaDPhZYjdCz+nSpszIh5 MyysSSCHtbclw== From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu , stable@kernel.org, Wenqing Liu Subject: [PATCH v2] f2fs: fix to do sanity check on summary info Date: Wed, 14 Sep 2022 19:51:51 +0800 Message-Id: <20220914115151.2994632-1-chao@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" As Wenqing Liu reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=3D216456 BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs] Read of size 4 at addr ffff8881464dcd80 by task mount/1013 CPU: 3 PID: 1013 Comm: mount Tainted: G W 6.0.0-rc4 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x45/0x5e print_report.cold+0xf3/0x68d kasan_report+0xa8/0x130 recover_data+0x63ae/0x6ae0 [f2fs] f2fs_recover_fsync_data+0x120d/0x1fc0 [f2fs] f2fs_fill_super+0x4665/0x61e0 [f2fs] mount_bdev+0x2cf/0x3b0 legacy_get_tree+0xed/0x1d0 vfs_get_tree+0x81/0x2b0 path_mount+0x47e/0x19d0 do_mount+0xce/0xf0 __x64_sys_mount+0x12c/0x1a0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The root cause is: in fuzzed image, SSA table is corrupted: ofs_in_node is larger than ADDRS_PER_PAGE(), result in out-of-range access on 4k-size page. - recover_data - do_recover_data - check_index_in_prev_nodes - f2fs_data_blkaddr This patch adds sanity check on summary info in recovery and GC flow in where the flows rely on them. After patch: [ 29.310883] F2FS-fs (loop0): Inconsistent ofs_in_node:65286 in summary, = ino:0, nid:6, max:1018 Cc: Reported-by: Wenqing Liu Signed-off-by: Chao Yu --- v2: - fix to avoid use uninitialized variable fs/f2fs/gc.c | 10 +++++++++- fs/f2fs/recovery.c | 15 ++++++++++++--- 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index fd400d148afb..3a820e5cdaee 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -1078,7 +1078,7 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct= f2fs_summary *sum, { struct page *node_page; nid_t nid; - unsigned int ofs_in_node; + unsigned int ofs_in_node, max_addrs; block_t source_blkaddr; =20 nid =3D le32_to_cpu(sum->nid); @@ -1104,6 +1104,14 @@ static bool is_alive(struct f2fs_sb_info *sbi, struc= t f2fs_summary *sum, return false; } =20 + max_addrs =3D IS_INODE(node_page) ? DEF_ADDRS_PER_INODE : + DEF_ADDRS_PER_BLOCK; + if (ofs_in_node >=3D max_addrs) { + f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, m= ax:%u", + ofs_in_node, dni->ino, dni->nid, max_addrs); + return false; + } + *nofs =3D ofs_of_node(node_page); source_blkaddr =3D data_blkaddr(NULL, node_page, ofs_in_node); f2fs_put_page(node_page, 1); diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c index 8326003e6918..5c9facec98f6 100644 --- a/fs/f2fs/recovery.c +++ b/fs/f2fs/recovery.c @@ -474,7 +474,7 @@ static int check_index_in_prev_nodes(struct f2fs_sb_inf= o *sbi, struct dnode_of_data tdn =3D *dn; nid_t ino, nid; struct inode *inode; - unsigned int offset; + unsigned int offset, ofs_in_node, max_addrs; block_t bidx; int i; =20 @@ -501,15 +501,24 @@ static int check_index_in_prev_nodes(struct f2fs_sb_i= nfo *sbi, got_it: /* Use the locked dnode page and inode */ nid =3D le32_to_cpu(sum.nid); + ofs_in_node =3D le16_to_cpu(sum.ofs_in_node); + + max_addrs =3D ADDRS_PER_PAGE(dn->node_page, dn->inode); + if (ofs_in_node >=3D max_addrs) { + f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%lu, nid:%u, = max:%u", + ofs_in_node, dn->inode->i_ino, nid, max_addrs); + return -EFSCORRUPTED; + } + if (dn->inode->i_ino =3D=3D nid) { tdn.nid =3D nid; if (!dn->inode_page_locked) lock_page(dn->inode_page); tdn.node_page =3D dn->inode_page; - tdn.ofs_in_node =3D le16_to_cpu(sum.ofs_in_node); + tdn.ofs_in_node =3D ofs_in_node; goto truncate_out; } else if (dn->nid =3D=3D nid) { - tdn.ofs_in_node =3D le16_to_cpu(sum.ofs_in_node); + tdn.ofs_in_node =3D ofs_in_node; goto truncate_out; } =20 --=20 2.25.1