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 --- tools/perf/util/cacheline.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 tools/perf/util/cacheline.h (limited to 'tools/perf/util/cacheline.h') diff --git a/tools/perf/util/cacheline.h b/tools/perf/util/cacheline.h new file mode 100644 index 000000000..fe6d5b60a --- /dev/null +++ b/tools/perf/util/cacheline.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef PERF_CACHELINE_H +#define PERF_CACHELINE_H + +#include + +int __pure cacheline_size(void); + + +/* + * Some architectures have 'Adjacent Cacheline Prefetch' feature, + * which performs like the cacheline size being doubled. + */ +static inline u64 cl_address(u64 address, bool double_cl) +{ + u64 size = cacheline_size(); + + if (double_cl) + size *= 2; + + /* return the cacheline of the address */ + return (address & ~(size - 1)); +} + +static inline u64 cl_offset(u64 address, bool double_cl) +{ + u64 size = cacheline_size(); + + if (double_cl) + size *= 2; + + /* return the offset inside cacheline */ + return (address & (size - 1)); +} + +#endif // PERF_CACHELINE_H -- cgit v1.3.1