From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() 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 Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- Documentation/userspace-api/index.rst | 71 +++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 Documentation/userspace-api/index.rst (limited to 'Documentation/userspace-api/index.rst') diff --git a/Documentation/userspace-api/index.rst b/Documentation/userspace-api/index.rst new file mode 100644 index 000000000..a68b1bea5 --- /dev/null +++ b/Documentation/userspace-api/index.rst @@ -0,0 +1,71 @@ +===================================== +The Linux kernel user-space API guide +===================================== + +.. _man-pages: https://www.kernel.org/doc/man-pages/ + +While much of the kernel's user-space API is documented elsewhere +(particularly in the man-pages_ project), some user-space information can +also be found in the kernel tree itself. This manual is intended to be the +place where this information is gathered. + + +System calls +============ + +.. toctree:: + :maxdepth: 1 + + unshare + futex2 + ebpf/index + ioctl/index + mseal + rseq + +Security-related interfaces +=========================== + +.. toctree:: + :maxdepth: 1 + + no_new_privs + seccomp_filter + landlock + lsm + mfd_noexec + spec_ctrl + tee + check_exec + +Devices and I/O +=============== + +.. toctree:: + :maxdepth: 1 + + accelerators/ocxl + dma-buf-heaps + dma-buf-alloc-exchange + fwctl/index + gpio/index + iommufd + media/index + dcdbas + vduse + isapnp + +Everything else +=============== + +.. toctree:: + :maxdepth: 1 + + ELF + liveupdate + netlink/index + sysfs-platform_profile + vduse + futex2 + perf_ring_buffer + ntsync -- cgit v1.3.1