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 0BB7E32B126; Sat, 12 Sep 2026 19:12:29 +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=1789240350; cv=none; b=bE5RoftaFA7SSP9ntHOAtWJmBQtC/Nv0BAY6VdQ38+tzCvkBUWpEbHJ8kKH1+QJNL0h5eMZdrU2qTfP4D9CDrrw5pcRfhm6RQFAJhx9y19nk+zgCv17u+GOQkU6F1J6UeeWSyqBIOFYx5toLVa3q6/Qdc5dBlJYQRX+x/TUw8Pw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789240350; c=relaxed/simple; bh=WdO5Jnah5XKHdp/6Gvgv2ny4h1NgZSjhWU3QhIwC27E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Yq223PywQIHnGB45dQ6KJT7qeOPp3P3gxKaXDyb6xVW9UgGii/LHg4zFS2lxZseC7VmVyinHym3jF0xDBGcet57KjFCO+9Gok8gnNRQrkdrz4fZyMnND3Is4ZL0Hq6JE+5TF+mYskFMtc2PTSt+gBrF3TdnmVunAMXpLUwA+M6g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ekYknS4s; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ekYknS4s" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1083C1F000FF; Sat, 12 Sep 2026 19:12:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789240348; bh=wxoyFhXPGld9WIardt0TQxKhY+qkyCIZWTGof44fzGg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ekYknS4shu944kAvdj67Ot5JD2kUGWbK8MCJx+Fwsq2QOS2A1Dy0R1uBnYG9V0BBx PB5o2zojyV/aWHAdVLEJuNR7HdQp2JoI+S/ZvLFs81qDBUkgMDUjS1JOb/nhl5+3Dz e0ksaO3UxEhY1gSBpl5msZGDcGBHQYoEvqJIWKEk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiang Mei , Weiming Shi , Konstantin Komarov , Sasha Levin Subject: [PATCH 5.15 849/935] fs/ntfs3: validate ef->size covers the records name and value Date: Sat, 12 Sep 2026 09:04:39 +0200 Message-ID: <20260912065546.301019922@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@linuxfoundation.org> User-Agent: quilt/0.69 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weiming Shi [ Upstream commit c22f91d82cb9a29d22bdffdce6c803467984ad0c ] When an EA record has a non-zero ef->size, ntfs_read_ea() only checks that the record fits in the remaining buffer (ea_size > bytes), not that ef->size is large enough to hold the record's own name_len + 1 + elength. A crafted image can pass validation with, e.g., ef->size = 24 but elength = 0xffff. ntfs_get_ea() then trusts elength and copies it out of the undersized record, reading past the kmalloc(info->size) allocation and leaking heap memory to userspace via getxattr(): BUG: KASAN: slab-out-of-bounds in ntfs_get_ea (fs/ntfs3/xattr.c:302) Read of size 65535 at addr ffff888100794550 by task exploit __asan_memcpy (mm/kasan/shadow.c:105) ntfs_get_ea (fs/ntfs3/xattr.c:302) ntfs_getxattr (fs/ntfs3/xattr.c:848) __vfs_getxattr (fs/xattr.c:441) vfs_getxattr (fs/xattr.c:474) do_getxattr (fs/xattr.c:800) path_getxattrat (fs/xattr.c:868) do_syscall_64 (arch/x86/entry/syscall_64.c:94) The buggy address is located 80 bytes inside of allocated 84-byte region in cache kmalloc-96 Compute the size the record needs and require ef->size to cover it. Fixes: 0e8235d28f3a ("fs/ntfs3: Check fields while reading") Reported-by: Xiang Mei Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Weiming Shi Signed-off-by: Konstantin Komarov Signed-off-by: Sasha Levin --- fs/ntfs3/xattr.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c index 84d0d8b46883f..d922d0c9cd7c7 100644 --- a/fs/ntfs3/xattr.c +++ b/fs/ntfs3/xattr.c @@ -145,26 +145,29 @@ static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea, for (off = 0; off < size; off += ea_size) { const struct EA_FULL *ef = Add2Ptr(ea_p, off); u32 bytes = size - off; + size_t need; /* Check if we can use field ea->size. */ if (bytes < sizeof(ef->size)) goto out1; + /* Check if we can use fields ef->name_len and ef->elength. */ + if (bytes < offsetof(struct EA_FULL, name)) + goto out1; + + /* Size needed to hold this record's name and value. */ + need = struct_size(ef, name, + 1 + ef->name_len + le16_to_cpu(ef->elength)); + if (ef->size) { ea_size = le32_to_cpu(ef->size); - if (ea_size > bytes) + /* ef->size must fit the list and cover the record. */ + if (ea_size > bytes || ea_size < need) goto out1; continue; } - /* Check if we can use fields ef->name_len and ef->elength. */ - if (bytes < offsetof(struct EA_FULL, name)) - goto out1; - - ea_size = ALIGN(struct_size(ef, name, - 1 + ef->name_len + - le16_to_cpu(ef->elength)), - 4); + ea_size = ALIGN(need, 4); if (ea_size > bytes) goto out1; } -- 2.53.0