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-versatile.c | 40 +++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 drivers/clocksource/timer-versatile.c (limited to 'drivers/clocksource/timer-versatile.c') diff --git a/drivers/clocksource/timer-versatile.c b/drivers/clocksource/timer-versatile.c new file mode 100644 index 000000000..f5d017b31 --- /dev/null +++ b/drivers/clocksource/timer-versatile.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Copyright (C) 2014 ARM Limited + */ + +#include +#include +#include +#include +#include + +#define SYS_24MHZ 0x05c + +static void __iomem *versatile_sys_24mhz; + +static u64 notrace versatile_sys_24mhz_read(void) +{ + return readl(versatile_sys_24mhz); +} + +static int __init versatile_sched_clock_init(struct device_node *node) +{ + void __iomem *base = of_iomap(node, 0); + + of_node_clear_flag(node, OF_POPULATED); + + if (!base) + return -ENXIO; + + versatile_sys_24mhz = base + SYS_24MHZ; + + sched_clock_register(versatile_sys_24mhz_read, 32, 24000000); + + return 0; +} +TIMER_OF_DECLARE(vexpress, "arm,vexpress-sysreg", + versatile_sched_clock_init); +TIMER_OF_DECLARE(versatile, "arm,versatile-sysreg", + versatile_sched_clock_init); -- cgit v1.3.1