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| author | Shivank Garg <shivankg@amd.com> | 2026-08-22 19:22:05 +0000 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2026-09-09 17:51:44 +0530 |
| commit | e873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch) | |
| tree | cc1ce1567f5b982359331863ebd9da38741f8d2e /Documentation/ABI/testing/debugfs-olpc | |
| download | linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.tar.gz linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.zip | |
dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted
When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.
dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:
slab-use-after-free in dma_chan_put+0x3e6/0x4c0
Read of size 8 by task insmod/6319
Freed by task 6319:
kfree+0x225/0x470
dma_chan_put+0x395/0x4c0
dmaengine_put+0xf8/0x160
Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device.
Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct")
Suggested-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'Documentation/ABI/testing/debugfs-olpc')
| -rw-r--r-- | Documentation/ABI/testing/debugfs-olpc | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/debugfs-olpc b/Documentation/ABI/testing/debugfs-olpc new file mode 100644 index 000000000..bd76cc6d5 --- /dev/null +++ b/Documentation/ABI/testing/debugfs-olpc @@ -0,0 +1,16 @@ +What: /sys/kernel/debug/olpc-ec/cmd +Date: Dec 2011 +KernelVersion: 3.4 +Contact: devel@lists.laptop.org +Description: + +A generic interface for executing OLPC Embedded Controller commands and +reading their responses. + +To execute a command, write data with the format: CC:N A A A A +CC is the (hex) command, N is the count of expected reply bytes, and A A A A +are optional (hex) arguments. + +To read the response (if any), read from the generic node after executing +a command. Hex reply bytes will be returned, *whether or not* they came from +the immediately previous command. |