From: Eric Dumazet <[email protected]>
Date: Sat, 23 Feb 2019 13:24:59 -0800
> syzbot was able to trigger another soft lockup [1]
>
> I first thought it was the O(N^2) issue I mentioned in my
> prior fix (f657d22ee1f "net/x25: do not hold the cpu
> too long in x25_new_lci()"), but I eventually found
> that x25_bind() was not checking SOCK_ZAPPED state under
> socket lock protection.
>
> This means that multiple threads can end up calling
> x25_insert_socket() for the same socket, and corrupt x25_list
...
> Fixes: 90c27297a9bf ("X.25 remove bkl in bind")
> Signed-off-by: Eric Dumazet <[email protected]>
> Cc: andrew hendry <[email protected]>
Applied and queued up for -stable, thanks Eric.
