Sažetak |
In the Linux kernel, the following vulnerability has been resolved:
atm: Revert atm_account_tx() if copy_from_iter_full() fails.
In vcc_sendmsg(), we account skb->truesize to sk->sk_wmem_alloc by
atm_account_tx().
It is expected to be reverted by atm_pop_raw() later called by
vcc->dev->ops->send(vcc, skb).
However, vcc_sendmsg() misses the same revert when copy_from_iter_full()
fails, and then we will leak a socket.
Let's factorise the revert part as atm_return_tx() and call it in
the failure path.
Note that the corresponding sk_wmem_alloc operation can be found in
alloc_tx() as of the blamed commit.
$ git blame -L:alloc_tx net/atm/common.c c55fa3cccbc2c~ |