From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.126.com (m16.mail.126.com [220.197.31.6]) (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 D8F0A1D9A70; Fri, 31 Jul 2026 01:23:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.6 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785461013; cv=none; b=kov/0HJWFsx2HJvkUhEoajFPXhBFK5QM5okkmQ3fmZnhFhBkSDiz1H0UFY3obCAHBqopbT7V/z6zsdvDTIcuzl1RIGdvPkrY6HVOMIj8RDTLyglrHV74xqSid14N0WmkhGAD/yAaa4ghYOqmVcQjdwhGJltdRm0QPLg6c0OajvY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785461013; c=relaxed/simple; bh=SYHfTPOMHblSRbVYvhhnOL85Ggh+FrsIMbmdemvvuZs=; h=Message-ID:Date:From:MIME-Version:To:CC:Subject:References: In-Reply-To:Content-Type; b=Cg35eQybPepZiPOdRELVNk73ffEqjVqIOT2RqEF1H0RPwcYwDFOJE+dzvC9yKftmeHKebIsPIU6WiwWhu6sfnJT9JedkkF5GJQ5EsEj0nreKQ9DibyQi0+KhApq5eyGmmU4p14EE0fwAJ1LACKIC/Uv+SV3ogjug3LKBeiN1wKg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com; spf=pass smtp.mailfrom=126.com; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b=Dw9xQg1S; arc=none smtp.client-ip=220.197.31.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=126.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b="Dw9xQg1S" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=Message-ID:Date:From:MIME-Version:To:Subject: Content-Type; bh=BF6Na6Ku0LPOsj8Vwwvh0x1v3lCEQ31aapXF3EdT6Z4=; b=Dw9xQg1SsgmFrqgc8K8cGmZRDGXW1RYNeO+KxuCJPexzicWB0UNrC513QXfpcD CKQraeAwzKSnpSm8sgiq5U0OGickCrPtfqy9fEAxTOg8Qpysh5PUF75o4XHv1dk8 +mFCfGk/v6AoypZEHQq5VU7Kk5pG4IjM4qiePZ8oRkvMc= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g0-0 (Coremail) with SMTP id _____wD3L9T4+Gtq_m4UEw--.14862S2; Fri, 31 Jul 2026 09:23:05 +0800 (CST) Message-ID: <6A6BF8E9.2070604@126.com> Date: Fri, 31 Jul 2026 09:22:49 +0800 From: Hongling Zeng User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 To: "Darrick J. Wong" , Hongling Zeng CC: cem@kernel.org, chandanrlinux@gmail.com, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3] xfs: fix heap buffer overflow in xfs_bmbt_to_bmdr References: <20260730094824.200669-1-zenghongling@kylinos.cn> <20260730154309.GB3556460@frogsfrogsfrogs> In-Reply-To: <20260730154309.GB3556460@frogsfrogsfrogs> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wD3L9T4+Gtq_m4UEw--.14862S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxuF1xXFWUGF4ftr45ArWrKrg_yoW5Cry3pr Z7t3Z0kFWvqw4xuFnF9w1rtw15u3ySy3yUCrZxAanxWwn8tr12qF9YkryY9w1jqa1SyrW0 gFn8AasrWwn8uFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07j-3kAUUUUU= X-CM-SenderInfo: x2kr0wpolqwiqxrzqiyswou0bp/xtbBoBnxwmpr+PknZQAA3I 在 2026年07月30日 23:43, Darrick J. Wong 写道: > Please take a breath and refrain from sending the same patch three times > in ninety minutes. Figure out what you want to change, run it through > some testing, and only send it once you've stopped finding things to > tweak. > > --D Thanks for the feedback. I apologize for the multiple versions - that was my mistake in not reviewing thoroughly enough before submitting. The v3 patch is in its final form. I would appreciate your review when you get a chance. Hongling > On Thu, Jul 30, 2026 at 05:48:24PM +0800, Hongling Zeng wrote: >> The xfs_bmbt_to_bmdr() function converts an in-memory btree root to >> on-disk form during log recovery. It uses bb_numrecs from the source >> to determine memcpy size without validating against the destination >> fork capacity. >> >> Current code: >> dmxr = xfs_bmdr_maxrecs(dblocklen, 0); // destination capacity >> ... >> dmxr = be16_to_cpu(dblock->bb_numrecs); // overwrite with source value! >> memcpy(..., * dmxr); // may overflow destination! >> >> If bb_numrecs is larger than the destination fork capacity, >> memcpy writes beyond the fork buffer, causing heap overflow. >> >> Fix by validating bb_numrecs against the destination capacity >> before using it for memcpy operations. >> >> Cc: stable@vger.kernel.org >> Fixes: 8ea5682d0711 ("xfs: refactor log recovery item dispatch for pass2 readhead functions") >> Signed-off-by: Hongling Zeng >> --- >> Change in v3: >> - Use dmxr for tpp calculation (on-disk format) and nrecs for memcpy (actual records) >> --- >> Change in v2: >> - Ensure memcpy operations consistently use nrecs instead of dmxr. >> --- >> fs/xfs/libxfs/xfs_bmap_btree.c | 12 +++++++++--- >> 1 file changed, 9 insertions(+), 3 deletions(-) >> >> diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c >> index 758a4b1ccf5b..a119053d67b5 100644 >> --- a/fs/xfs/libxfs/xfs_bmap_btree.c >> +++ b/fs/xfs/libxfs/xfs_bmap_btree.c >> @@ -151,6 +151,7 @@ xfs_bmbt_to_bmdr( >> int dmxr; >> xfs_bmbt_key_t *fkp; >> __be64 *fpp; >> + int nrecs; >> xfs_bmbt_key_t *tkp; >> __be64 *tpp; >> >> @@ -167,14 +168,19 @@ xfs_bmbt_to_bmdr( >> ASSERT(rblock->bb_level != 0); >> dblock->bb_level = rblock->bb_level; >> dblock->bb_numrecs = rblock->bb_numrecs; >> + >> + /* Validate record count against destination fork capacity */ >> + nrecs = be16_to_cpu(rblock->bb_numrecs); >> dmxr = xfs_bmdr_maxrecs(dblocklen, 0); >> + if (nrecs > dmxr) >> + return; >> + >> fkp = xfs_bmbt_key_addr(mp, rblock, 1); >> tkp = xfs_bmdr_key_addr(dblock, 1); >> fpp = xfs_bmap_broot_ptr_addr(mp, rblock, 1, rblocklen); >> tpp = xfs_bmdr_ptr_addr(dblock, 1, dmxr); >> - dmxr = be16_to_cpu(dblock->bb_numrecs); >> - memcpy(tkp, fkp, sizeof(*fkp) * dmxr); >> - memcpy(tpp, fpp, sizeof(*fpp) * dmxr); >> + memcpy(tkp, fkp, sizeof(*fkp) * nrecs); >> + memcpy(tpp, fpp, sizeof(*fpp) * nrecs); >> } >> >> STATIC struct xfs_btree_cur * >> -- >> 2.25.1 >> >>