Description

In the Linux kernel, the following vulnerability has been resolved:

net: ethernet: ti: am65-cpsw: fix freeing IRQ in am65_cpsw_nuss_remove_tx_chns()

When getting the IRQ we use k3_udma_glue_tx_get_irq() which returns
negative error value on error. So not NULL check is not sufficient
to deteremine if IRQ is valid. Check that IRQ is greater then zero
to ensure it is valid.

There is no issue at probe time but at runtime user can invoke
.set_channels which results in the following call chain.
am65_cpsw_set_channels()
am65_cpsw_nuss_update_tx_rx_chns()
am65_cpsw_nuss_remove_tx_chns()
am65_cpsw_nuss_init_tx_chns()

At this point if am65_cpsw_nuss_init_tx_chns() fails due to
k3_udma_glue_tx_get_irq() then tx_chn->irq will be set to a
negative value.

Then, at subsequent .set_channels with higher channel count we
will attempt to free an invalid IRQ in am65_cpsw_nuss_remove_tx_chns()
leading to a kernel warning.

The issue is present in the original commit that introduced this driver,
although there, am65_cpsw_nuss_update_tx_rx_chns() existed as
am65_cpsw_nuss_update_tx_chns().

Classification

CVE ID: CVE-2025-21799

Affected Products

Vendor: Linux, Linux

Product: Linux, Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 9.23% (scored less or equal to compared to others)

EPSS Date: 2025-03-28 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-21799
https://git.kernel.org/stable/c/aea5cca681d268f794fa2385f9ec26a5cce025cd
https://git.kernel.org/stable/c/88fd5db8c0073bd91d18391feb5741aeb0a2b475
https://git.kernel.org/stable/c/8448c87b3af68bebca21e3136913f7f77e363515
https://git.kernel.org/stable/c/8aae91ae1c65782a169ec070e023d4d269e5d6e6
https://git.kernel.org/stable/c/4395a44acb15850e492dd1de9ec4b6479d96bc80

Timeline