CVE-2025-40032

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

PCI: endpoint: pci-epf-test: Add NULL check for DMA channels before release

The fields dma_chan_tx and dma_chan_rx of the struct pci_epf_test can be

NULL even after EPF initialization. Then it is prudent to check that

they have non-NULL values before releasing the channels. Add the checks

in pci_epf_test_clean_dma_chan().

Without the checks, NULL pointer dereferences happen and they can lead

to a kernel panic in some cases:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050

Call trace:

dma_release_channel+0x2c/0x120 (P)

pci_epf_test_epc_deinit+0x94/0xc0 [pci_epf_test]

pci_epc_deinit_notify+0x74/0xc0

tegra_pcie_ep_pex_rst_irq+0x250/0x5d8

irq_thread_fn+0x34/0xb8

irq_thread+0x18c/0x2e8

kthread+0x14c/0x210

ret_from_fork+0x10/0x20

[mani: trimmed the stack trace]