linux-kernel - Re: [PATCH net] ethtool: fix stack overflow in ethnl_parse

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20201209155540.7217ee8a@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com>
Date:   Wed, 9 Dec 2020 15:55:40 -0800
From:   Jakub Kicinski <kuba@...nel.org>
To:     Michal Kubecek <mkubecek@...e.cz>
Cc:     "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH net] ethtool: fix stack overflow in ethnl_parse_bitset()

On Tue,  8 Dec 2020 23:13:51 +0100 (CET) Michal Kubecek wrote:
> Syzbot reported a stack overflow in bitmap_from_arr32() called from
> ethnl_parse_bitset() when bitset from netlink message is longer than
> target bitmap length. While ethnl_compact_sanity_checks() makes sure that
> trailing part is all zeros (i.e. the request does not try to touch bits
> kernel does not recognize), we also need to cap change_bits to nbits so
> that we don't try to write past the prepared bitmaps.
> 
> Fixes: 88db6d1e4f62 ("ethtool: add ethnl_parse_bitset() helper")
> Reported-by: syzbot+9d39fa49d4df294aab93@...kaller.appspotmail.com
> Signed-off-by: Michal Kubecek <mkubecek@...e.cz>

Applied, thank you!