From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A71D43375C1; Mon, 18 Aug 2025 13:19:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755523169; cv=none; b=rDsgdJpByy2HXzTC6eQArQUCndug0C2PanEmk7QljQohPM0PIgqtSbgA3RqDanTcAsCzoVol6VybWFmpQtvhQkOx07N5q2cRVNQOx1wq2npC3u9rXcQzgu7V0Sr2LYiLS87V8Rl6rY+7z8PbcXljRO23ryhfMvQUEWscrieJxdM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755523169; c=relaxed/simple; bh=g2P6YZ+OTKa6wwY3twsSXFb13ymoRKuyhygStiOYWow=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oUHFdH8s4TcU6vahPSIUZqNF9F3Av8YSpg7z042sxOrFrqB1G319xAYeSkT7HjG2JDyzudEp4KqdSUhgOuHJy/dcqsu5jrpBKvrFCzFkohF1DMKSPJfmj6tpSuCqYTOlldcfAp6oXbEQIWUvy3EwQmPQeC0inL/Ptt7pE/SRERc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ecOBKksX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ecOBKksX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18603C4CEEB; Mon, 18 Aug 2025 13:19:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755523169; bh=g2P6YZ+OTKa6wwY3twsSXFb13ymoRKuyhygStiOYWow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ecOBKksXw/Yxh1K5chHYw9xLXQkqgenDl667j3kJUrOOuTh0BvJXmZzDvy7DmHsYi 92Jzxf6UALl8XVSRApX/0g0uRBUgsoNHktYjZpwb2CLrC9k4o2KQH7iNtgB7RjPPWh M+QpwRUCeO2h34E8buZgCTdyZXFOSvwVCNrG4TvY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+4708579bb230a0582a57@syzkaller.appspotmail.com, Andrew Price , Andreas Gruenbacher , Sasha Levin Subject: [PATCH 6.15 092/515] gfs2: Validate i_depth for exhash directories Date: Mon, 18 Aug 2025 14:41:18 +0200 Message-ID: <20250818124501.925521646@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250818124458.334548733@linuxfoundation.org> References: <20250818124458.334548733@linuxfoundation.org> User-Agent: quilt/0.68 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 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Price [ Upstream commit 557c024ca7250bb65ae60f16c02074106c2f197b ] A fuzzer test introduced corruption that ends up with a depth of 0 in dir_e_read(), causing an undefined shift by 32 at: index = hash >> (32 - dip->i_depth); As calculated in an open-coded way in dir_make_exhash(), the minimum depth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is invalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time. So we can avoid the undefined behaviour by checking for depth values lower than the minimum in gfs2_dinode_in(). Values greater than the maximum are already being checked for there. Also switch the calculation in dir_make_exhash() to use ilog2() to clarify how the depth is calculated. Tested with the syzkaller repro.c and xfstests '-g quick'. Reported-by: syzbot+4708579bb230a0582a57@syzkaller.appspotmail.com Signed-off-by: Andrew Price Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin --- fs/gfs2/dir.c | 6 ++---- fs/gfs2/glops.c | 6 ++++++ 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c index dbf1aede744c..509e2f0d97e7 100644 --- a/fs/gfs2/dir.c +++ b/fs/gfs2/dir.c @@ -60,6 +60,7 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" @@ -912,7 +913,6 @@ static int dir_make_exhash(struct inode *inode) struct qstr args; struct buffer_head *bh, *dibh; struct gfs2_leaf *leaf; - int y; u32 x; __be64 *lp; u64 bn; @@ -979,9 +979,7 @@ static int dir_make_exhash(struct inode *inode) i_size_write(inode, sdp->sd_sb.sb_bsize / 2); gfs2_add_inode_blocks(&dip->i_inode, 1); dip->i_diskflags |= GFS2_DIF_EXHASH; - - for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ; - dip->i_depth = y; + dip->i_depth = ilog2(sdp->sd_hash_ptrs); gfs2_dinode_out(dip, dibh->b_data); diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c index 116efe335c32..0cf9da2ef622 100644 --- a/fs/gfs2/glops.c +++ b/fs/gfs2/glops.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" @@ -450,6 +451,11 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf) gfs2_consist_inode(ip); return -EIO; } + if ((ip->i_diskflags & GFS2_DIF_EXHASH) && + depth < ilog2(sdp->sd_hash_ptrs)) { + gfs2_consist_inode(ip); + return -EIO; + } ip->i_depth = (u8)depth; ip->i_entries = be32_to_cpu(str->di_entries); -- 2.39.5