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 --- io_uring/uring_cmd.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 io_uring/uring_cmd.h (limited to 'io_uring/uring_cmd.h') diff --git a/io_uring/uring_cmd.h b/io_uring/uring_cmd.h new file mode 100644 index 000000000..041aef8a8 --- /dev/null +++ b/io_uring/uring_cmd.h @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +struct io_async_cmd { + struct iou_vec vec; + struct io_uring_sqe sqes[2]; +}; + +int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags); +int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +void io_uring_cmd_sqe_copy(struct io_kiocb *req); +void io_uring_cmd_cleanup(struct io_kiocb *req); + +bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, + struct io_uring_task *tctx, bool cancel_all); + +bool io_uring_cmd_post_mshot_cqe32(struct io_uring_cmd *cmd, + unsigned int issue_flags, + struct io_uring_cqe cqe[2]); + +void io_cmd_cache_free(const void *entry); + +int io_cmd_poll_multishot(struct io_uring_cmd *cmd, + unsigned int issue_flags, __poll_t mask); -- cgit v1.3.1