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/nolibc/math.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 tools/include/nolibc/math.h (limited to 'tools/include/nolibc/math.h') diff --git a/tools/include/nolibc/math.h b/tools/include/nolibc/math.h new file mode 100644 index 000000000..9df823ddd --- /dev/null +++ b/tools/include/nolibc/math.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ +/* + * math definitions for NOLIBC + * Copyright (C) 2025 Thomas Weißschuh + */ + +/* make sure to include all global symbols */ +#include "nolibc.h" + +#ifndef _NOLIBC_SYS_MATH_H +#define _NOLIBC_SYS_MATH_H + +static __inline__ +double fabs(double x) +{ + return x >= 0 ? x : -x; +} + +static __inline__ +float fabsf(float x) +{ + return x >= 0 ? x : -x; +} + +static __inline__ +long double fabsl(long double x) +{ + return x >= 0 ? x : -x; +} + +#endif /* _NOLIBC_SYS_MATH_H */ -- cgit v1.3.1