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| author | Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> | 2025-10-14 12:14:06 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-19 16:23:20 +0200 |
| commit | 6411f840a9b5c47c00ca8e004733de232553870d (patch) | |
| tree | 953dbe0af82e019341bea701ea98f552a0cd43d7 | |
| parent | 3477a98c1ab60ca85da205020fb095721a166a59 (diff) | |
| download | linux-6411f840a9b5c47c00ca8e004733de232553870d.tar.gz linux-6411f840a9b5c47c00ca8e004733de232553870d.tar.bz2 linux-6411f840a9b5c47c00ca8e004733de232553870d.zip | |
PCI: endpoint: pci-epf-test: Add NULL check for DMA channels before release
[ Upstream commit 85afa9ea122dd9d4a2ead104a951d318975dcd25 ]
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
Fixes: 8353813c88ef ("PCI: endpoint: Enable DMA tests for endpoints with DMA capabilities")
Fixes: 5ebf3fc59bd2 ("PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
[mani: trimmed the stack trace]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250916025756.34807-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/pci/endpoint/functions/pci-epf-test.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 4ebc49f1a467..3fe2187cdd0b 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -282,15 +282,20 @@ static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test) if (!epf_test->dma_supported) return; - dma_release_channel(epf_test->dma_chan_tx); - if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { + if (epf_test->dma_chan_tx) { + dma_release_channel(epf_test->dma_chan_tx); + if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { + epf_test->dma_chan_tx = NULL; + epf_test->dma_chan_rx = NULL; + return; + } epf_test->dma_chan_tx = NULL; - epf_test->dma_chan_rx = NULL; - return; } - dma_release_channel(epf_test->dma_chan_rx); - epf_test->dma_chan_rx = NULL; + if (epf_test->dma_chan_rx) { + dma_release_channel(epf_test->dma_chan_rx); + epf_test->dma_chan_rx = NULL; + } } static void pci_epf_test_print_rate(const char *ops, u64 size, |