Date:   Thu, 23 Feb 2023 10:11:39 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Fedor Pchelkin <pchelkin@ispras.ru>
Cc:     stable@vger.kernel.org, Johannes Berg <johannes@sipsolutions.net>,
        Pavel Skripkin <paskripkin@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Bob Copeland <me@bobcopeland.com>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Alexey Khoroshilov <khoroshilov@ispras.ru>,
        lvc-project@linuxtesting.org,
        syzbot+860268315ba86ea6b96b@syzkaller.appspotmail.com,
        Johannes Berg <johannes.berg@intel.com>
Subject: Re: [PATCH 5.4/5.10 1/1] mac80211: mesh: embedd mesh_paths and
 mpp_paths into ieee80211_if_mesh
Message-ID: <Y/ctyzCtbPwyrrDI@kroah.com>
References: <20230222200301.254791-1-pchelkin@ispras.ru>
 <20230222200301.254791-2-pchelkin@ispras.ru>
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On Wed, Feb 22, 2023 at 11:03:01PM +0300, Fedor Pchelkin wrote:
> From: Pavel Skripkin <paskripkin@gmail.com>
> 
> commit 8b5cb7e41d9d77ffca036b0239177de123394a55 upstream.
> 
> Syzbot hit NULL deref in rhashtable_free_and_destroy(). The problem was
> in mesh_paths and mpp_paths being NULL.
> 
> mesh_pathtbl_init() could fail in case of memory allocation failure, but
> nobody cared, since ieee80211_mesh_init_sdata() returns void. It led to
> leaving 2 pointers as NULL. Syzbot has found null deref on exit path,
> but it could happen anywhere else, because code assumes these pointers are
> valid.
> 
> Since all ieee80211_*_setup_sdata functions are void and do not fail,
> let's embedd mesh_paths and mpp_paths into parent struct to avoid
> adding error handling on higher levels and follow the pattern of others
> setup_sdata functions
> 
> Fixes: 60854fd94573 ("mac80211: mesh: convert path table to rhashtable")
> Reported-and-tested-by: syzbot+860268315ba86ea6b96b@syzkaller.appspotmail.com
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> Link: https://lore.kernel.org/r/20211230195547.23977-1-paskripkin@gmail.com
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> [pchelkin@ispras.ru: adapt a comment spell fixing issue]
> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
> ---

This also worked for 4.19.y, but not 4.14.y, care to also fix it there?

thanks,

greg k-h