CVE-2025-38190: atm: Revert atm_account_tx() if copy_from_iter_full() fails.

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-04 · updated 2026-06-17

Description

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~

Affected products

Debian Linux: 11.0
Linux kernel: from 2.6.13 before 5.4.295; from 5.5 before 5.10.239; from 5.11 before 5.15.186; from 5.16 before 6.1.142; from 6.2 before 6.6.95; from 6.7 before 6.12.35 — fixed in 5.10.239, 5.15.186, 5.4.295, 6.1.142, 6.12.35, 6.15.4

How to fix

Upgrade to a fixed version: Linux kernel 5.10.239, 5.15.186, 5.4.295, 6.1.142. Check the vendor advisory for mitigations.

References

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