From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 500FB3546F4 for ; Thu, 10 Sep 2026 01:26:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789003576; cv=none; b=hlfsXR6AWa45Zd0VaOhzfu44NV6jgSCvq34a6nLCzOQSKXDiRLJOo/6eXOB+xIIKR4MfIJqR2UFDZ0xVYBtDOXOmotnQeukzbLp1lw7U2/OHG/47TxGHelu/Cf+DbGooZg+yyGjg5yFL0qC6D8xiY8SHtZu21ElyYXqESuu9jWY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789003576; c=relaxed/simple; bh=zfO2b0uqkNFsHhSFBTRYCikor7k9swZKKtU6VEjuoDM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tfPv26SWDuPBkgn4xxRuNQjW/wxAA8H7qNxAAw13KNIs401SYlAyyiOqpmrIUGmJas/M8ahUQNHRw2SeDyYTnubTu2XD82JW59GSFDqSJMnbg03MsSJxUyFrp6A/J7M5Dbei24LXkub9wjMBuzamWW+XOApjM1XgikqFLHVIVe0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FenfbCik; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FenfbCik" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A6641F000FF; Thu, 10 Sep 2026 01:26:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789003575; bh=5OpQreAgXcWdX6jXWOaB+foX2uIAJpyimt9Vx1ePUv0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FenfbCikfIi1U68a6Xi17dipXutNLe1K++ePKeqmwQRr4+EnIWmehqnsFQzYfFYE/ FlnxVuICigQTH7BfGuIbr7cfb7ETDwId1R57xX+7zQ7nQLQUI0IaQty83GMy7sQX+T eiCwxnC5pbf5ki2YzpQYpzmA1tczZAVxTj8D1m7s0jR4dzhBlRl6WdAzZgcP0Uy72l yunomMBAHRf7N/oPNIg3Ivk7FODyKEPeJjJQfDbHW310/NfaCQfzX5dNsF/R7bDI+0 yKGc8PPtj7Cp/xa3/0ElIC/636ZBSpdF+WSmQUqNlUNfBhpRXTI4+MUTsxQrln9Nt8 R7upW5Y7aHH7w== From: Sasha Levin To: stable@vger.kernel.org Cc: =?UTF-8?q?HE=20WEI=EF=BC=88=E3=82=AE=E3=82=AB=E3=82=AF=EF=BC=89?= , Konstantin Komarov , Sasha Levin Subject: [PATCH 6.12.y 4/4] fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list() Date: Wed, 9 Sep 2026 21:26:10 -0400 Message-ID: <20260910012610.3866859-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260910012610.3866859-1-sashal@kernel.org> References: <2026090803-refract-segment-1a96@gregkh> <20260910012610.3866859-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: HE WEI（ギカク） [ Upstream commit 7c4841e2a62794a3bab7c1ff0540580f387e377f ] ni_create_attr_list() allocates a fixed buffer of al_aligned(record_size) (== record_size) bytes and then walks every attribute of the primary MFT record, writing one ATTR_LIST_ENTRY per attribute and advancing the cursor by le_size(name_len), with no check against the end of the buffer; the total size is only computed after the loop. A minimum-size resident attribute occupies SIZEOF_RESIDENT (0x18 = 24) bytes on disk, but an unnamed attribute expands to le_size(0) (0x20 = 32) bytes in the list. Because the number of attributes in a record is not bounded (mi_enum_attr() accepts arbitrarily many equal-type, nameless minimum-size attributes), a crafted record packed with such attributes produces a list larger than record_size and overflows the heap buffer. This is reachable from a crafted, loop-mounted NTFS image: opening the file and adding an attribute (e.g. via setxattr) drives ntfs_set_ea() -> ni_insert_resident() -> ni_insert_attr() -> ni_ins_attr_ext() -> ni_create_attr_list(). BUG: KASAN: slab-out-of-bounds in ni_create_attr_list+0xc48/0x1058 Write of size 4 at addr ffff000008984c00 by task setfattr/345 ni_create_attr_list+0xc48/0x1058 ni_ins_attr_ext+0x510/0x7c0 ni_insert_attr+0x3f8/0x70c ni_insert_resident+0xc8/0x3b0 ntfs_set_ea+0x66c/0xd28 ntfs_setxattr+0x4d8/0x5b0 __arm64_sys_setxattr+0xa4/0x124 Allocated by task 345: ni_create_attr_list+0x188/0x1058 The buggy address belongs to the cache kmalloc-1k of size 1024 (the write lands at object+1024). Size the buffer from the actual attributes instead of assuming a single record_size is always enough. Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation") Reported-by: HE WEI（ギカク） Signed-off-by: HE WEI（ギカク） Signed-off-by: Konstantin Komarov Signed-off-by: Sasha Levin --- fs/ntfs3/frecord.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c index 162a6c038000e..45e8d73d38f8f 100644 --- a/fs/ntfs3/frecord.c +++ b/fs/ntfs3/frecord.c @@ -823,10 +823,23 @@ int ni_create_attr_list(struct ntfs_inode *ni) rs = sbi->record_size; /* - * Skip estimating exact memory requirement. - * Looks like one record_size is always enough. + * Compute the exact size of the attribute list. Each attribute in the + * record yields one ATTR_LIST_ENTRY of le_size(name_len) bytes. The + * minimum on-disk attribute is SIZEOF_RESIDENT (0x18) bytes, but an + * unnamed one expands to le_size(0) (0x20) here, so a record crafted + * with many such attributes needs more than a single record_size; the + * previous fixed kzalloc(record_size) could therefore be overflowed by + * an attacker-controlled record. */ - le = kzalloc(al_aligned(rs), GFP_NOFS); + lsize = 0; + attr = NULL; + while ((attr = mi_enum_attr(ni, &ni->mi, attr))) + lsize += le_size(attr->name_len); + + if (!lsize) + return -EINVAL; + + le = kzalloc(al_aligned(lsize), GFP_NOFS); if (!le) return -ENOMEM; @@ -836,7 +849,6 @@ int ni_create_attr_list(struct ntfs_inode *ni) attr = NULL; nb = 0; free_b = 0; - attr = NULL; for (; (attr = mi_enum_attr(ni, &ni->mi, attr)); le = Add2Ptr(le, sz)) { sz = le_size(attr->name_len); -- 2.53.0