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 --- drivers/clocksource/timer-probe.c | 45 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 drivers/clocksource/timer-probe.c (limited to 'drivers/clocksource/timer-probe.c') diff --git a/drivers/clocksource/timer-probe.c b/drivers/clocksource/timer-probe.c new file mode 100644 index 000000000..b7860bc0d --- /dev/null +++ b/drivers/clocksource/timer-probe.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. + */ + +#include +#include +#include +#include + +extern struct of_device_id __timer_of_table[]; + +static const struct of_device_id __timer_of_table_sentinel + __used __section("__timer_of_table_end"); + +void __init timer_probe(void) +{ + struct device_node *np; + const struct of_device_id *match; + of_init_fn_1_ret init_func_ret; + unsigned timers = 0; + int ret; + + for_each_matching_node_and_match(np, __timer_of_table, &match) { + if (!of_device_is_available(np)) + continue; + + init_func_ret = match->data; + + ret = init_func_ret(np); + if (ret) { + if (ret != -EPROBE_DEFER) + pr_err("Failed to initialize '%pOF': %d\n", np, + ret); + continue; + } + + timers++; + } + + timers += acpi_probe_device_table(timer); + + if (!timers) + pr_crit("%s: no matching timers found\n", __func__); +} -- cgit v1.3.1