Bug 2376395 (CVE-2025-38190)

Summary: CVE-2025-38190 kernel: atm: Revert atm_account_tx() if copy_from_iter_full() fails.
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-07-04 14:03:41 UTC 
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~
Comment 1 Avinash Hanwate 2025-07-07 04:29:55 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025070414-CVE-2025-38190-5b22@gregkh/T