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/rw.h | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 io_uring/rw.h (limited to 'io_uring/rw.h') diff --git a/io_uring/rw.h b/io_uring/rw.h new file mode 100644 index 000000000..1179506f9 --- /dev/null +++ b/io_uring/rw.h @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include + +struct io_meta_state { + u32 seed; + struct iov_iter_state iter_meta; +}; + +struct io_async_rw { + struct iou_vec vec; + size_t bytes_done; + + struct_group(clear, + struct iov_iter iter; + struct iov_iter_state iter_state; + struct iovec fast_iov; + unsigned buf_group; + + /* + * wpq is for buffered io, while meta fields are used with + * direct io + */ + union { + struct wait_page_queue wpq; + struct { + struct uio_meta meta; + struct io_meta_state meta_state; + }; + }; + ); +}; + +int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_readv_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_writev_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_readv(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_read(struct io_kiocb *req, unsigned int issue_flags); +int io_write(struct io_kiocb *req, unsigned int issue_flags); +int io_read_fixed(struct io_kiocb *req, unsigned int issue_flags); +int io_write_fixed(struct io_kiocb *req, unsigned int issue_flags); +void io_readv_writev_cleanup(struct io_kiocb *req); +void io_rw_fail(struct io_kiocb *req); +void io_req_rw_complete(struct io_tw_req tw_req, io_tw_token_t tw); +int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags); +void io_rw_cache_free(const void *entry); -- cgit v1.3.1