From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D09606FAF for ; Mon, 28 Aug 2023 10:15:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 546C7C433C7; Mon, 28 Aug 2023 10:15:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693217717; bh=OraIY93WInB+Ts3O3iciWnHfucrmjeOYEEI6kZ2DP4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ya8eLQQcTZHXEPfqMklSpdPD31MNY1ncr2j3hk5DZEbJUWlCFgS581lffMyIaqaGM iRCgxkvTxFwgtrb+LmoKBsmrrtfzuqhufVrsu5ieT4EFOPN/9rfZXWr6KXDF1KsOqj H5wtyzLJt7zZrPlaCOa6caNio50kAWeroURYsP40= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+853a6f4dfa3cf37d3aea@syzkaller.appspotmail.com, Yogesh , Dave Kleikamp , Sasha Levin Subject: [PATCH 4.14 07/57] fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev Date: Mon, 28 Aug 2023 12:12:27 +0200 Message-ID: <20230828101144.458707607@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101144.231099710@linuxfoundation.org> References: <20230828101144.231099710@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yogesh [ Upstream commit 4e302336d5ca1767a06beee7596a72d3bdc8d983 ] Syzkaller reported the following issue: UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:1965:6 index -84 is out of range for type 's8[341]' (aka 'signed char[341]') CPU: 1 PID: 4995 Comm: syz-executor146 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 ubsan_epilogue lib/ubsan.c:217 [inline] __ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348 dbAllocDmapLev+0x3e5/0x430 fs/jfs/jfs_dmap.c:1965 dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1809 dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1350 dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:874 dtSplitUp fs/jfs/jfs_dtree.c:974 [inline] dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:863 jfs_create+0x7b6/0xbb0 fs/jfs/namei.c:137 lookup_open fs/namei.c:3492 [inline] open_last_lookups fs/namei.c:3560 [inline] path_openat+0x13df/0x3170 fs/namei.c:3788 do_filp_open+0x234/0x490 fs/namei.c:3818 do_sys_openat2+0x13f/0x500 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x247/0x290 fs/open.c:1383 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f1f4e33f7e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc21129578 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f4e33f7e9 RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c RBP: 00007f1f4e2ff080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f4e2ff110 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 The bug occurs when the dbAllocDmapLev()function attempts to access dp->tree.stree[leafidx + LEAFIND] while the leafidx value is negative. To rectify this, the patch introduces a safeguard within the dbAllocDmapLev() function. A check has been added to verify if leafidx is negative. If it is, the function immediately returns an I/O error, preventing any further execution that could potentially cause harm. Tested via syzbot. Reported-by: syzbot+853a6f4dfa3cf37d3aea@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=ae2f5a27a07ae44b0f17 Signed-off-by: Yogesh Signed-off-by: Dave Kleikamp Signed-off-by: Sasha Levin --- fs/jfs/jfs_dmap.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index cc2ac1f324b08..464ddaf8ebd10 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -2040,6 +2040,9 @@ dbAllocDmapLev(struct bmap * bmp, if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx)) return -ENOSPC; + if (leafidx < 0) + return -EIO; + /* determine the block number within the file system corresponding * to the leaf at which free space was found. */ -- 2.40.1