Messages in this thread | | | From | Eric Dumazet <> | Date | Mon, 6 Feb 2023 09:29:51 +0100 | Subject | Re: [PATCH net-next v3 2/3] tun: tun_chr_open(): correctly initialize socket uid |
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On Sat, Feb 4, 2023 at 6:39 PM Pietro Borrello <borrello@diag.uniroma1.it> wrote: > > sock_init_data() assumes that the `struct socket` passed in input is > contained in a `struct socket_alloc` allocated with sock_alloc(). > However, tun_chr_open() passes a `struct socket` embedded in a `struct > tun_file` allocated with sk_alloc(). > This causes a type confusion when issuing a container_of() with > SOCK_INODE() in sock_init_data() which results in assigning a wrong > sk_uid to the `struct sock` in input. > On default configuration, the type confused field overlaps with the > high 4 bytes of `struct tun_struct __rcu *tun` of `struct tun_file`, > NULL at the time of call, which makes the uid of all tun sockets 0, > i.e., the root one. > Fix the assignment by using sock_init_data_uid(). > > Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.") > Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> > ---
Reviewed-by: Eric Dumazet <edumazet@google.com> Thanks.
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