From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-82.freemail.mail.aliyun.com (out30-82.freemail.mail.aliyun.com [115.124.30.82]) (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 E1C1417BED0 for ; Fri, 3 Apr 2026 05:52:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.82 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775195576; cv=none; b=ZXv8S6i7u4o8iAwf4KqD8aMClGQUUqcYpE58NH7Cgz0atIxZsAMMaEfGy0LGc3Lnwoeav03kNpOyXMJ0R8fmsK4SZ3CZZJKNEieP7sfSd1mqpyB+3P45iE5V2ttZBXlktCeRRo3yKpQCVfaTnQnod3uDwf5fgljQdRCFKPEFPww= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775195576; c=relaxed/simple; bh=6xE3SZfloQY71Rk+nUAwFe1Dg4FM83bJlRdLbCyRHl4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mXokaA7vbJsPK3pKv4jgDgx77osSeh19GhKgmVaL/rkAxhwDW0LRs7Tlk72REPX5vYgwdk/A3/56XQ4BtTSbUkQ33AePLszJLepKGG7jUFYbRT6epzKIe5oINx+MsF1mb5KOahTjKxZ+Upz7XqqxFJal/mcwj7QLUrCM3RlUynw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=aliyun.com; spf=pass smtp.mailfrom=aliyun.com; dkim=pass (1024-bit key) header.d=aliyun.com header.i=@aliyun.com header.b=Iyxfdhk/; arc=none smtp.client-ip=115.124.30.82 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=aliyun.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aliyun.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=aliyun.com header.i=@aliyun.com header.b="Iyxfdhk/" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=aliyun.com; s=s1024; t=1775195571; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=rgm+g1A45XQpmUs2srHEu1Xem9ZdNdpscc1UOLbIjJE=; b=Iyxfdhk/s1wUpVV0UpC6sJnw2wa57aSZLXgaHGNW0lrNlqOAqg5nH+YEouviWfbUXcxIzOx6FD3zzRTzfKCcS2CaRc5T5HOYMVbGH30tzE1oO3FOD5gnwaTJNGojhISN7816ReAxRN+xZqkb6J8WpEXDSTAxuJaW921yqtAOGn8= X-Alimail-AntiSpam:AC=CONTINUE;BC=0.0735963|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_system_inform|0.0687734-0.00541231-0.925814;FP=2233420379857546455|0|0|0|0|-1|-1|-1;HT=maildocker-contentspam033037026112;MF=ruohanlan@aliyun.com;NM=1;PH=DS;RN=7;RT=7;SR=0;TI=SMTPD_---0X0JIJ2H_1775195569; Received: from Ubuntu24(mailfrom:ruohanlan@aliyun.com fp:SMTPD_---0X0JIJ2H_1775195569 cluster:ay36) by smtp.aliyun-inc.com; Fri, 03 Apr 2026 13:52:50 +0800 From: Ruohan Lan To: gregkh@linuxfoundation.org, stable@vger.kernel.org Cc: gfs2@lists.linux.dev, Andrew Price , syzbot+4708579bb230a0582a57@syzkaller.appspotmail.com, Andreas Gruenbacher , Ruohan Lan Subject: [PATCH 6.6.y 2/2] gfs2: Validate i_depth for exhash directories Date: Fri, 3 Apr 2026 13:51:54 +0800 Message-ID: <20260403055154.4206-2-ruohanlan@aliyun.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260403055154.4206-1-ruohanlan@aliyun.com> References: <20260403055154.4206-1-ruohanlan@aliyun.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 --- 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 c252400e5999..c4e9488483d9 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 2ec0b6871ae9..f575cd8ff47c 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" @@ -466,6 +467,11 @@ 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); -- 2.43.0