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/include/asm/barrier.h | 65 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 tools/include/asm/barrier.h (limited to 'tools/include/asm/barrier.h') diff --git a/tools/include/asm/barrier.h b/tools/include/asm/barrier.h new file mode 100644 index 000000000..0c21678ac --- /dev/null +++ b/tools/include/asm/barrier.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#if defined(__i386__) || defined(__x86_64__) +#include "../../arch/x86/include/asm/barrier.h" +#elif defined(__arm__) +#include "../../arch/arm/include/asm/barrier.h" +#elif defined(__aarch64__) +#include "../../arch/arm64/include/asm/barrier.h" +#elif defined(__powerpc__) +#include "../../arch/powerpc/include/asm/barrier.h" +#elif defined(__riscv) +#include "../../arch/riscv/include/asm/barrier.h" +#elif defined(__s390__) +#include "../../arch/s390/include/asm/barrier.h" +#elif defined(__sh__) +#include "../../arch/sh/include/asm/barrier.h" +#elif defined(__sparc__) +#include "../../arch/sparc/include/asm/barrier.h" +#elif defined(__tile__) +#include "../../arch/tile/include/asm/barrier.h" +#elif defined(__alpha__) +#include "../../arch/alpha/include/asm/barrier.h" +#elif defined(__mips__) +#include "../../arch/mips/include/asm/barrier.h" +#elif defined(__ia64__) +#include "../../arch/ia64/include/asm/barrier.h" +#elif defined(__xtensa__) +#include "../../arch/xtensa/include/asm/barrier.h" +#else +#include +#endif + +/* + * Generic fallback smp_*() definitions for archs that haven't + * been updated yet. + */ + +#ifndef smp_rmb +# define smp_rmb() rmb() +#endif + +#ifndef smp_wmb +# define smp_wmb() wmb() +#endif + +#ifndef smp_mb +# define smp_mb() mb() +#endif + +#ifndef smp_store_release +# define smp_store_release(p, v) \ +do { \ + smp_mb(); \ + WRITE_ONCE(*p, v); \ +} while (0) +#endif + +#ifndef smp_load_acquire +# define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = READ_ONCE(*p); \ + smp_mb(); \ + ___p1; \ +}) +#endif -- cgit v1.3.1