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/testing/shared/maple-shared.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 tools/testing/shared/maple-shared.h (limited to 'tools/testing/shared/maple-shared.h') diff --git a/tools/testing/shared/maple-shared.h b/tools/testing/shared/maple-shared.h new file mode 100644 index 000000000..2a1e9a859 --- /dev/null +++ b/tools/testing/shared/maple-shared.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#ifndef __MAPLE_SHARED_H__ +#define __MAPLE_SHARED_H__ + +#define CONFIG_DEBUG_MAPLE_TREE +#define CONFIG_MAPLE_SEARCH +#define MAPLE_32BIT (MAPLE_NODE_SLOTS > 31) +#include "shared.h" +#include +#include +#include "linux/init.h" + +void maple_rcu_cb(struct rcu_head *head); +#define rcu_cb maple_rcu_cb + +#define kfree_rcu(_struct, _memb) \ +do { \ + typeof(_struct) _p_struct = (_struct); \ + \ + call_rcu(&((_p_struct)->_memb), rcu_cb); \ +} while(0); + + +#endif /* __MAPLE_SHARED_H__ */ -- cgit v1.3.1