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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:   Fri, 9 Oct 2020 18:26:31 -0700
From:   Jakub Kicinski <>
To:     Cong Wang <>
        Xin Long <>, Jon Maloy <>,
        Ying Xue <>
Subject: Re: [Patch net] tipc: fix the skb_unshare() in tipc_buf_append()

On Wed,  7 Oct 2020 21:12:50 -0700 Cong Wang wrote:
> skb_unshare() drops a reference count on the old skb unconditionally,
> so in the failure case, we end up freeing the skb twice here.
> And because the skb is allocated in fclone and cloned by caller
> tipc_msg_reassemble(), the consequence is actually freeing the
> original skb too, thus triggered the UAF by syzbot.
> Fix this by replacing this skb_unshare() with skb_cloned()+skb_copy().
> Fixes: ff48b6222e65 ("tipc: use skb_unshare() instead in tipc_buf_append()")
> Reported-and-tested-by:
> Cc: Xin Long <>
> Cc: Jon Maloy <>
> Cc: Ying Xue <>
> Signed-off-by: Cong Wang <>

Applied and queued for stable, thank you!

Powered by blists - more mailing lists