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authorPietro Borrello <borrello@diag.uniroma1.it>2023-02-04 17:39:22 +0000
committerDavid S. Miller <davem@davemloft.net>2023-02-06 10:16:55 +0000
commit66b2c338adce580dfce2199591e65e2bab889cff (patch)
treedb2d69568ee3cbce31d03565f18468eb6f63f628 /drivers/net/tap.c
parenta096ccca6e503a5c575717ff8a36ace27510ab0a (diff)
tap: tap_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, tap_open() passes a `struct socket` embedded in a `struct tap_queue` 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 padding bytes between `int vnet_hdr_sz` and `struct tap_dev __rcu *tap` in `struct tap_queue`, which makes the uid of all tap 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>
Diffstat (limited to 'drivers/net/tap.c')
-rw-r--r--drivers/net/tap.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index a2be1994b389..8941aa199ea3 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -533,7 +533,7 @@ static int tap_open(struct inode *inode, struct file *file)
q->sock.state = SS_CONNECTED;
q->sock.file = file;
q->sock.ops = &tap_socket_ops;
- sock_init_data(&q->sock, &q->sk);
+ sock_init_data_uid(&q->sock, &q->sk, inode->i_uid);
q->sk.sk_write_space = tap_sock_write_space;
q->sk.sk_destruct = tap_sock_destruct;
q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;