atm: Revert atm_account_tx() if copy_from_iter_full() fails.

Summary

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~

Timeline

1. Jul 4, 2025, 1:37 PM UTCCVE published
2. May 11, 2026, 9:22 PM UTCRecord last updated

Affected versions

• Linux Linux

  Version range not reported

• Linux Linux

  2.6.12

References 8