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 A7A51344DB9; Sat, 30 May 2026 17:41:41 +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=1780162902; cv=none; b=MJfHYETL7Is7WhG0o1PKaEZyg86pGnzkFrgkzmDRIravMKQvHFWf7ilRMdgWCFxpLHG8D8M9Z7J7QU29YJHawBh/fspoX4OzuCCVckz0SBHdmHG5xEG5eOsBRWEZXOfLfIdqzKQ9ferd8W6cj6a6ZqFEKlNAQ/DZQbDB5EZRKpc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162902; c=relaxed/simple; bh=f9oZlv8DqsIZOks8bW54sAc0A9BlHIfSbmpSSD1yTf8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XDCgwn9HuBPUIKSUn5OPAywPQd24wvHDEC0nJ134T+UcL1BaPceM4oZW1QLhlbJ8oJKgghUkn3CooAm3mAx3544qEKNS0qI34TBklRIIbgeBGBhyfsmMmj9IwEh0jbHCU9gRKPJZwf82urIyNdPq94ktiVYVqTf9OvjgyM19S5c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dHi6FMw0; 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="dHi6FMw0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA6011F00893; Sat, 30 May 2026 17:41:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780162901; bh=4UiVDNCNB3LLpn57bwbw3PjpsuGh+fyNSYZ+IdR2Tnw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dHi6FMw0MC/KZWWIwR45NEnrX17nVfk++Kxs09eHF80o6hLuAtrOxAL3yaj0iMhkm fDpoXTBY/rcQ6GcVcn4lrpl2G5PkQz79u2NPsMAz2x5m6rl1Y1UgJurBq2mVun2LS5 BQhuJ2rETgnIriAhAUdatLdyzsETC0w6HodPyYY4= 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 , Ruohan Lan , Sasha Levin Subject: [PATCH 5.15 096/776] gfs2: Validate i_depth for exhash directories Date: Sat, 30 May 2026 17:56:50 +0200 Message-ID: <20260530160242.818774335@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@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: 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: Ruohan Lan 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 e1bdc4b0608c2..559cad553db62 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 fdbae357727b2..8a077de9ee0a4 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" @@ -459,6 +460,11 @@ 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); -- 2.53.0