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author | Pietro Borrello <borrello@diag.uniroma1.it> | 2023-02-04 17:39:21 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2023-02-06 10:16:55 +0000 |
commit | a096ccca6e503a5c575717ff8a36ace27510ab0a (patch) | |
tree | 110ccd5a50aa1c7f5bc239db16f7253f80e7356f | |
parent | 584f3742890e966d2f0a1f3c418c9ead70b2d99e (diff) | |
download | linux-a096ccca6e503a5c575717ff8a36ace27510ab0a.tar.gz linux-a096ccca6e503a5c575717ff8a36ace27510ab0a.tar.bz2 linux-a096ccca6e503a5c575717ff8a36ace27510ab0a.zip |
tun: tun_chr_open(): correctly initialize socket uid
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | drivers/net/tun.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index a7d17c680f4a..745131b2d6db 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3448,7 +3448,7 @@ static int tun_chr_open(struct inode *inode, struct file * file) tfile->socket.file = file; tfile->socket.ops = &tun_socket_ops; - sock_init_data(&tfile->socket, &tfile->sk); + sock_init_data_uid(&tfile->socket, &tfile->sk, inode->i_uid); tfile->sk.sk_write_space = tun_sock_write_space; tfile->sk.sk_sndbuf = INT_MAX; |