From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (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 70EC22D97B8 for ; Mon, 11 May 2026 06:26:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778480779; cv=none; b=PmYabced4Gfm152572itKbn90U4F1JUjmWGNKbCw3fxeezotpnfF4OuiurLsIcMQl5CFxAi0CPCruZMJ7ZlSRr1/2JBemHTb+u7u5aWwXzNqaR3ZJ7Qgh+9f8DA+udx07QKcI3/BRk6yRi7vOwEIdUdFnArHySw418ZBph9l5Wk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778480779; c=relaxed/simple; bh=8dOcgGL/cHnE31qLvoMvHLmWVCMb2fZcJLPw5qS4QIE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=PnWoYbXAvpvb4rlt909VQqLY4sJQMpchFEuMtR8AKeSYU/EXIJ7fMYmmvPAOQ6LReXJryCdbUdtB8FTXE83uVkLopkZphZpsX6efmBPJAjSYelMfl3vleV6uvhhhyzdU/t76v02QdB1p0M1Li08nenbyeIT+CIWh7H4SvJabPC4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=LC0leMRT; arc=none smtp.client-ip=115.124.30.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="LC0leMRT" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1778480770; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=kMcRzqueSAvp/+1oEdvXaUzTOSWWakrhZfAhvPb1iNM=; b=LC0leMRTYUE03BbyPKN2huEY/BMpSsMxGn+OAWX8ZftRcR/IIg7rdC5oFgQlJ/rjIrkoMwgJQTGXU1SFAFAOhf8Uw9/FUu27gtCiNxCgQfw6Hjy/f8yQulF2aUsOTHttKegMQhKZg3fVjvp2EaHxoqHTL3PpjAOmmQZkdzDSkIY= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033045133197;MF=joseph.qi@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0X2ff.P6_1778480769; Received: from 30.221.128.206(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0X2ff.P6_1778480769 cluster:ay36) by smtp.aliyun-inc.com; Mon, 11 May 2026 14:26:10 +0800 Message-ID: <5d1b0c85-fa4c-400c-b432-95260b311673@linux.alibaba.com> Date: Mon, 11 May 2026 14:26:09 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/5] ocfs2: validate inline xattr header before ibody lookups To: ZhengYuan Huang , akpm Cc: ocfs2-devel@lists.linux.dev, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com, r33s3n6@gmail.com, zzzccc427@gmail.com, Mark Fasheh , Joel Becker References: <20260508085914.61647-1-gality369@gmail.com> <20260508085914.61647-2-gality369@gmail.com> From: Joseph Qi In-Reply-To: <20260508085914.61647-2-gality369@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/8/26 4:59 PM, ZhengYuan Huang wrote: > [BUG] > mknodat() can read past the end of a dinode block when ACL inheritance > walks a corrupted inode-body xattr header. Another report shows the same > unchecked lookup later faulting in the VFS open path after create > returns a garbage status. > > KASAN: use-after-free in > ocfs2_xattr_find_entry+0x37b/0x3a0 fs/ocfs2/xattr.c:1078 > Read of size 2 at addr ffff88801c520300 by task syz.0.10/360 > > Trace: > ... > ocfs2_xattr_find_entry+0x37b/0x3a0 fs/ocfs2/xattr.c:1078 > ocfs2_xattr_ibody_get fs/ocfs2/xattr.c:1178 [inline] > ocfs2_xattr_get_nolock+0x2ee/0x1110 fs/ocfs2/xattr.c:1309 > ocfs2_calc_xattr_init+0x716/0xac0 fs/ocfs2/xattr.c:628 > ocfs2_mknod+0x935/0x2400 fs/ocfs2/namei.c:333 > ocfs2_create+0x158/0x390 fs/ocfs2/namei.c:676 > vfs_create fs/namei.c:3493 [inline] > vfs_create+0x445/0x6f0 fs/namei.c:3477 > do_mknodat+0x2d8/0x5e0 fs/namei.c:4372 > __do_sys_mknodat fs/namei.c:4400 [inline] > __se_sys_mknodat fs/namei.c:4397 [inline] > __x64_sys_mknodat+0xb6/0xf0 fs/namei.c:4397 > ... > > Another report: > BUG: unable to handle page fault for address: fffffbfff3e40ec0 > RIP: 0010:__d_entry_type include/linux/dcache.h:414 [inline] > RIP: 0010:d_can_lookup include/linux/dcache.h:429 [inline] > RIP: 0010:d_is_dir include/linux/dcache.h:439 [inline] > RIP: 0010:path_openat+0xe2f/0x2ce0 fs/namei.c:4134 > > Trace: > ... > do_filp_open+0x1f6/0x430 fs/namei.c:4161 > do_sys_openat2+0x117/0x1c0 fs/open.c:1437 > __x64_sys_openat+0x15b/0x220 fs/open.c:1463 > ... > > [CAUSE] > ocfs2_xattr_ibody_list() already validates the inline xattr size and > entry count, but ocfs2_xattr_ibody_get() and ocfs2_xattr_ibody_find() > still derive the inline header directly from di->i_xattr_inline_size and > then trust xh_count. A corrupted inline size or entry count can therefore > move the computed header outside the dinode block before get/find start > walking it. That can either make ocfs2_xattr_find_entry() dereference > xs->header->xh_count outside the block or make ocfs2_xattr_get_nolock() > bubble a garbage status back through ocfs2_calc_xattr_init() into the > create/open path. > > [FIX] > Factor the existing ibody header geometry checks into a shared helper. > Use it in ocfs2_xattr_ibody_get() and ocfs2_xattr_ibody_find(), and have > ocfs2_xattr_ibody_list() reuse the same helper instead of open-coding > the validation. Reject corrupt ibody metadata with -EFSCORRUPTED before > the lookup path can walk bogus xattr geometry or return a garbage status. > > Signed-off-by: ZhengYuan Huang Looks fine. Reviewed-by: Joseph Qi > --- > fs/ocfs2/xattr.c | 82 +++++++++++++++++++++++++++--------------------- > 1 file changed, 47 insertions(+), 35 deletions(-) > > diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c > index 86cfd4c2adf9..3a5a17cdcf7e 100644 > --- a/fs/ocfs2/xattr.c > +++ b/fs/ocfs2/xattr.c > @@ -950,6 +950,41 @@ static int ocfs2_xattr_list_entries(struct inode *inode, > return result; > } > > +static int ocfs2_xattr_ibody_lookup_header(struct inode *inode, > + struct ocfs2_dinode *di, > + struct ocfs2_xattr_header **header) > +{ > + u16 xattr_count; > + size_t max_entries; > + u16 inline_size = le16_to_cpu(di->i_xattr_inline_size); > + > + if (inline_size > inode->i_sb->s_blocksize || > + inline_size < sizeof(struct ocfs2_xattr_header)) { > + ocfs2_error(inode->i_sb, > + "Invalid xattr inline size %u in inode %llu\n", > + inline_size, > + (unsigned long long)OCFS2_I(inode)->ip_blkno); > + return -EFSCORRUPTED; > + } > + > + *header = (struct ocfs2_xattr_header *) > + ((void *)di + inode->i_sb->s_blocksize - inline_size); > + > + xattr_count = le16_to_cpu((*header)->xh_count); > + max_entries = (inline_size - sizeof(struct ocfs2_xattr_header)) / > + sizeof(struct ocfs2_xattr_entry); > + > + if (xattr_count > max_entries) { > + ocfs2_error(inode->i_sb, > + "xattr entry count %u exceeds maximum %zu in inode %llu\n", > + xattr_count, max_entries, > + (unsigned long long)OCFS2_I(inode)->ip_blkno); > + return -EFSCORRUPTED; > + } > + > + return 0; > +} > + > int ocfs2_has_inline_xattr_value_outside(struct inode *inode, > struct ocfs2_dinode *di) > { > @@ -975,39 +1010,13 @@ static int ocfs2_xattr_ibody_list(struct inode *inode, > struct ocfs2_xattr_header *header = NULL; > struct ocfs2_inode_info *oi = OCFS2_I(inode); > int ret = 0; > - u16 xattr_count; > - size_t max_entries; > - u16 inline_size; > > if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) > return ret; > > - inline_size = le16_to_cpu(di->i_xattr_inline_size); > - > - /* Validate inline size is reasonable */ > - if (inline_size > inode->i_sb->s_blocksize || > - inline_size < sizeof(struct ocfs2_xattr_header)) { > - ocfs2_error(inode->i_sb, > - "Invalid xattr inline size %u in inode %llu\n", > - inline_size, > - (unsigned long long)OCFS2_I(inode)->ip_blkno); > - return -EFSCORRUPTED; > - } > - > - header = (struct ocfs2_xattr_header *) > - ((void *)di + inode->i_sb->s_blocksize - inline_size); > - > - xattr_count = le16_to_cpu(header->xh_count); > - max_entries = (inline_size - sizeof(struct ocfs2_xattr_header)) / > - sizeof(struct ocfs2_xattr_entry); > - > - if (xattr_count > max_entries) { > - ocfs2_error(inode->i_sb, > - "xattr entry count %u exceeds maximum %zu in inode %llu\n", > - xattr_count, max_entries, > - (unsigned long long)OCFS2_I(inode)->ip_blkno); > - return -EFSCORRUPTED; > - } > + ret = ocfs2_xattr_ibody_lookup_header(inode, di, &header); > + if (ret) > + return ret; > > ret = ocfs2_xattr_list_entries(inode, header, buffer, buffer_size); > > @@ -1200,8 +1209,9 @@ static int ocfs2_xattr_ibody_get(struct inode *inode, > return -ENODATA; > > xs->end = (void *)di + inode->i_sb->s_blocksize; > - xs->header = (struct ocfs2_xattr_header *) > - (xs->end - le16_to_cpu(di->i_xattr_inline_size)); > + ret = ocfs2_xattr_ibody_lookup_header(inode, di, &xs->header); > + if (ret) > + return ret; > xs->base = (void *)xs->header; > xs->here = xs->header->xh_entries; > > @@ -2726,12 +2736,14 @@ static int ocfs2_xattr_ibody_find(struct inode *inode, > > xs->xattr_bh = xs->inode_bh; > xs->end = (void *)di + inode->i_sb->s_blocksize; > - if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) > - xs->header = (struct ocfs2_xattr_header *) > - (xs->end - le16_to_cpu(di->i_xattr_inline_size)); > - else > + if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) { > + ret = ocfs2_xattr_ibody_lookup_header(inode, di, &xs->header); > + if (ret) > + return ret; > + } else { > xs->header = (struct ocfs2_xattr_header *) > (xs->end - OCFS2_SB(inode->i_sb)->s_xattr_inline_size); > + } > xs->base = (void *)xs->header; > xs->here = xs->header->xh_entries; >