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-sp.h | 63 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/clocksource/timer-sp.h (limited to 'drivers/clocksource/timer-sp.h') diff --git a/drivers/clocksource/timer-sp.h b/drivers/clocksource/timer-sp.h new file mode 100644 index 000000000..811f840be --- /dev/null +++ b/drivers/clocksource/timer-sp.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ARM timer implementation, found in Integrator, Versatile and Realview + * platforms. Not all platforms support all registers and bits in these + * registers, so we mark them with A for Integrator AP, C for Integrator + * CP, V for Versatile and R for Realview. + * + * Integrator AP has 16-bit timers, Integrator CP, Versatile and Realview + * can have 16-bit or 32-bit selectable via a bit in the control register. + * + * Every SP804 contains two identical timers. + */ +#define NR_TIMERS 2 +#define TIMER_1_BASE 0x00 +#define TIMER_2_BASE 0x20 + +#define TIMER_LOAD 0x00 /* ACVR rw */ +#define TIMER_VALUE 0x04 /* ACVR ro */ +#define TIMER_CTRL 0x08 /* ACVR rw */ +#define TIMER_CTRL_ONESHOT (1 << 0) /* CVR */ +#define TIMER_CTRL_32BIT (1 << 1) /* CVR */ +#define TIMER_CTRL_DIV1 (0 << 2) /* ACVR */ +#define TIMER_CTRL_DIV16 (1 << 2) /* ACVR */ +#define TIMER_CTRL_DIV256 (2 << 2) /* ACVR */ +#define TIMER_CTRL_IE (1 << 5) /* VR */ +#define TIMER_CTRL_PERIODIC (1 << 6) /* ACVR */ +#define TIMER_CTRL_ENABLE (1 << 7) /* ACVR */ + +#define TIMER_INTCLR 0x0c /* ACVR wo */ +#define TIMER_RIS 0x10 /* CVR ro */ +#define TIMER_MIS 0x14 /* CVR ro */ +#define TIMER_BGLOAD 0x18 /* CVR rw */ + +struct sp804_timer { + int load; + int load_h; + int value; + int value_h; + int ctrl; + int intclr; + int ris; + int mis; + int bgload; + int bgload_h; + int timer_base[NR_TIMERS]; + int width; +}; + +struct sp804_clkevt { + void __iomem *base; + void __iomem *load; + void __iomem *load_h; + void __iomem *value; + void __iomem *value_h; + void __iomem *ctrl; + void __iomem *intclr; + void __iomem *ris; + void __iomem *mis; + void __iomem *bgload; + void __iomem *bgload_h; + unsigned long reload; + int width; +}; -- cgit v1.3.1