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 C8739415F23; Tue, 21 Jul 2026 21:54:25 +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=1784670867; cv=none; b=TP4S4WLEixiF16Ibj8qAzUzdpN6yX7M45VJly7eYRkoauPajYua42X8NqeV6wTVnk+E6fdan6p1hg9TEg0ml+XOS+SrdUyWx9eNorf4NeypywYoFZ91tTIF8rANQ0+BOuyO29QLpvbJDtmLdcdiMfu/3aY/HAHnrVVySBltpBDE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784670867; c=relaxed/simple; bh=mqEAP2HVD0MFyhPIpwpiEoi/mVGZ94aJ6ZN8hA62+1A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gAyMvf+BSWz4tapk8UGSQZdN/s9bj5Ln1+/dKggrjkoo19iwK7vGwGGcFapLiZwEDSuiKL51678T8f1xG5oXLC5du9nlgjQx59LY1zwn598M+BsOv9lEgnAQmkfBC2sAAb1vXEjRIDNoL3/iUfeOOW5E0YpmEPvG3GeFpVb4BPU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SjolB96W; 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="SjolB96W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F92B1F000E9; Tue, 21 Jul 2026 21:54:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784670865; bh=7ZdZyGeGBPqvHMuwl6O33nEaMWzImgH5AdHZGhZr6go=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=SjolB96WObu/EeyyQYF4bDlxLuinKEAMka0CHON/JpZg0DMXpTkjLYWx2DJTvEh8m O5IFdT2/jXKv0encpw3VEyANg8H9SNZCp7+2aGfMXiAsmhRzH5QRjl7Zn/jQiAFDml FmUN7yI52CFmCsfNArgXoPB0Lkgf8JxXaL18wAJo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Chao Yu , Jaegeuk Kim , Sasha Levin Subject: [PATCH 5.15 030/843] f2fs: bound i_inline_xattr_size for non-inline-xattr inodes Date: Tue, 21 Jul 2026 17:14:25 +0200 Message-ID: <20260721152406.648417237@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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: Bryam Vargas [ Upstream commit 378acf3cf19b6af6cba55e8dd1154c4e1504bae8 ] When the flexible_inline_xattr feature is enabled, do_read_inode() loads the on-disk i_inline_xattr_size unconditionally: if (f2fs_sb_has_flexible_inline_xattr(sbi)) fi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size); but sanity_check_inode() only range-checks it when the inode also has the FI_INLINE_XATTR flag set. An inode that carries an inline dentry or inline data but not FI_INLINE_XATTR -- the normal layout for an inline directory -- therefore keeps a fully attacker-controlled i_inline_xattr_size from a crafted image. get_inline_xattr_addrs() returns that value with no flag gating, so it feeds the inode geometry: MAX_INLINE_DATA() = 4 * (CUR_ADDRS_PER_INODE - i_inline_xattr_size - 1) NR_INLINE_DENTRY() = MAX_INLINE_DATA() * BITS_PER_BYTE / (...) addrs_per_page() = CUR_ADDRS_PER_INODE - i_inline_xattr_size A large i_inline_xattr_size drives MAX_INLINE_DATA() and NR_INLINE_DENTRY() negative, so make_dentry_ptr_inline() sets d->max (int) to a negative value. The inline directory walk then compares an unsigned long bit_pos against that negative d->max, which is promoted to a huge unsigned bound, and reads far past the inline area: while (bit_pos < d->max) /* fs/f2fs/dir.c */ ... test_bit_le(bit_pos, d->bitmap) / d->dentry[bit_pos] ... Mounting a crafted image and reading such a directory triggers an out-of-bounds read in f2fs_fill_dentries(); the same underflow also corrupts ADDRS_PER_INODE for regular files. Validate i_inline_xattr_size against MAX_INLINE_XATTR_SIZE whenever the flexible_inline_xattr feature is enabled -- i.e. whenever the value is loaded from disk and consumed -- and keep the lower MIN_INLINE_XATTR_SIZE bound gated on inodes that actually carry an inline xattr, so legitimate inodes with i_inline_xattr_size == 0 are still accepted. Cc: stable@vger.kernel.org Fixes: 6afc662e68b5 ("f2fs: support flexible inline xattr size") Signed-off-by: Bryam Vargas Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/inode.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -258,14 +258,15 @@ static bool sanity_check_inode(struct in return false; } - if (f2fs_has_extra_attr(inode) && - f2fs_sb_has_flexible_inline_xattr(sbi) && - f2fs_has_inline_xattr(inode) && - (!fi->i_inline_xattr_size || - fi->i_inline_xattr_size > MAX_INLINE_XATTR_SIZE)) { + if (f2fs_sb_has_flexible_inline_xattr(sbi) && + (fi->i_inline_xattr_size > MAX_INLINE_XATTR_SIZE || + (f2fs_has_inline_xattr(inode) && + fi->i_inline_xattr_size < + sizeof(struct f2fs_xattr_header) / sizeof(__le32)))) { set_sbi_flag(sbi, SBI_NEED_FSCK); - f2fs_warn(sbi, "%s: inode (ino=%lx) has corrupted i_inline_xattr_size: %d, max: %zu", + f2fs_warn(sbi, "%s: inode (ino=%lx) has corrupted i_inline_xattr_size: %d, min: %zu, max: %zu", __func__, inode->i_ino, fi->i_inline_xattr_size, + sizeof(struct f2fs_xattr_header) / sizeof(__le32), MAX_INLINE_XATTR_SIZE); return false; }