Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:[EOL][EOL]PCI: endpoint: pci-epf-test: Add NULL check for DMA channels before release[EOL][EOL]The fields dma_chan_tx and dma_chan_rx of the struct pci_epf_test can be[EOL]NULL even after EPF initialization. Then it is prudent to check that[EOL]they have non-NULL values before releasing the channels. Add the checks[EOL]in pci_epf_test_clean_dma_chan().[EOL][EOL]Without the checks, NULL pointer dereferences happen and they can lead[EOL]to a kernel panic in some cases:[EOL][EOL]  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050[EOL]  Call trace:[EOL]   dma_release_channel+0x2c/0x120 (P)[EOL]   pci_epf_test_epc_deinit+0x94/0xc0 [pci_epf_test][EOL]   pci_epc_deinit_notify+0x74/0xc0[EOL]   tegra_pcie_ep_pex_rst_irq+0x250/0x5d8[EOL]   irq_thread_fn+0x34/0xb8[EOL]   irq_thread+0x18c/0x2e8[EOL]   kthread+0x14c/0x210[EOL]   ret_from_fork+0x10/0x20[EOL][EOL][mani: trimmed the stack trace]