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 --- rust/helpers/mm.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 rust/helpers/mm.c (limited to 'rust/helpers/mm.c') diff --git a/rust/helpers/mm.c b/rust/helpers/mm.c new file mode 100644 index 000000000..b5540997b --- /dev/null +++ b/rust/helpers/mm.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +__rust_helper void rust_helper_mmgrab(struct mm_struct *mm) +{ + mmgrab(mm); +} + +__rust_helper void rust_helper_mmdrop(struct mm_struct *mm) +{ + mmdrop(mm); +} + +__rust_helper void rust_helper_mmget(struct mm_struct *mm) +{ + mmget(mm); +} + +__rust_helper bool rust_helper_mmget_not_zero(struct mm_struct *mm) +{ + return mmget_not_zero(mm); +} + +__rust_helper void rust_helper_mmap_read_lock(struct mm_struct *mm) +{ + mmap_read_lock(mm); +} + +__rust_helper bool rust_helper_mmap_read_trylock(struct mm_struct *mm) +{ + return mmap_read_trylock(mm); +} + +__rust_helper void rust_helper_mmap_read_unlock(struct mm_struct *mm) +{ + mmap_read_unlock(mm); +} + +__rust_helper struct vm_area_struct * +rust_helper_vma_lookup(struct mm_struct *mm, unsigned long addr) +{ + return vma_lookup(mm, addr); +} + +__rust_helper void rust_helper_vma_end_read(struct vm_area_struct *vma) +{ + vma_end_read(vma); +} -- cgit v1.3.1