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 A3ED535CB6B; Mon, 9 Feb 2026 14:27:53 +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=1770647273; cv=none; b=Y99xTAh20jLXi6MdDGVusD5DP6uddLeWRJLO98GPJU5UzkT7P2UU+WfUZLCUMTTn5t9kuhazl/6tWwDDwYh36BbQjRNZaZYOfT7NRvhxiJXS47kxnm8JEbSWFBnZcmLPB46tUH//uYFSyOkm08Z75oU02x3rmMe/tCgotdHGp18= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770647273; c=relaxed/simple; bh=PVAj38ZhDD7DrIrbwB1cBQkSwfvr09Li0DfWKi/9Mdg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hfpoIRcfL68mfldDGEl19CHKIFhrP9aOldILdi/yFoAUcERFoAf0fnXfpRehxD2l298LR0XDheMW/XdlNIy8SmblwrBcj1l1uk2+BiNiNgjNep/Fd2cwQId6uf9P1TZ9XGHoFnDS89Fviy2OTy/oH8zdN69vaOH0UHZTU8qbjw8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1BWt+m8z; 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="1BWt+m8z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18230C116C6; Mon, 9 Feb 2026 14:27:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770647273; bh=PVAj38ZhDD7DrIrbwB1cBQkSwfvr09Li0DfWKi/9Mdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1BWt+m8zj7nVvy5aJnq7k5y0sqweKCld5kG+SZt8FfzhO4Fgazs062KmGCmW9APlv HSt4o4mJuUP8CQlVikIFg4WLz5jKzbkF8Jv4HB+iqzfCrRkyZxKYpwJd3YgZEqWSNC 1pt5CppT4P83aLgpM+24zajxNKKptwHB6dzWcABA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Helge Deller , Daniel Vogelbacher , Viacheslav Dubeyko , Ilya Dryomov Subject: [PATCH 6.18 017/175] ceph: fix oops due to invalid pointer for kfree() in parse_longname() Date: Mon, 9 Feb 2026 15:21:30 +0100 Message-ID: <20260209142321.096064117@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260209142320.474120190@linuxfoundation.org> References: <20260209142320.474120190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Vogelbacher commit bc8dedae022ce3058659c3addef3ec4b41d15e00 upstream. This fixes a kernel oops when reading ceph snapshot directories (.snap), for example by simply running `ls /mnt/my_ceph/.snap`. The variable str is guarded by __free(kfree), but advanced by one for skipping the initial '_' in snapshot names. Thus, kfree() is called with an invalid pointer. This patch removes the need for advancing the pointer so kfree() is called with correct memory pointer. Steps to reproduce: 1. Create snapshots on a cephfs volume (I've 63 snaps in my testcase) 2. Add cephfs mount to fstab $ echo "samba-fileserver@.files=/volumes/datapool/stuff/3461082b-ecc9-4e82-8549-3fd2590d3fb6 /mnt/test/stuff ceph acl,noatime,_netdev 0 0" >> /etc/fstab 3. Reboot the system $ systemctl reboot 4. Check if it's really mounted $ mount | grep stuff 5. List snapshots (expected 63 snapshots on my system) $ ls /mnt/test/stuff/.snap Now ls hangs forever and the kernel log shows the oops. Cc: stable@vger.kernel.org Fixes: 101841c38346 ("[ceph] parse_longname(): strrchr() expects NUL-terminated string") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220807 Suggested-by: Helge Deller Signed-off-by: Daniel Vogelbacher Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman --- fs/ceph/crypto.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -219,12 +219,13 @@ static struct inode *parse_longname(cons struct ceph_vino vino = { .snap = CEPH_NOSNAP }; char *name_end, *inode_number; int ret = -EIO; - /* NUL-terminate */ - char *str __free(kfree) = kmemdup_nul(name, *name_len, GFP_KERNEL); + /* Snapshot name must start with an underscore */ + if (*name_len <= 0 || name[0] != '_') + return ERR_PTR(-EIO); + /* Skip initial '_' and NUL-terminate */ + char *str __free(kfree) = kmemdup_nul(name + 1, *name_len - 1, GFP_KERNEL); if (!str) return ERR_PTR(-ENOMEM); - /* Skip initial '_' */ - str++; name_end = strrchr(str, '_'); if (!name_end) { doutc(cl, "failed to parse long snapshot name: %s\n", str);