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 --- arch/mips/bcm63xx/dev-uart.c | 77 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 arch/mips/bcm63xx/dev-uart.c (limited to 'arch/mips/bcm63xx/dev-uart.c') diff --git a/arch/mips/bcm63xx/dev-uart.c b/arch/mips/bcm63xx/dev-uart.c new file mode 100644 index 000000000..5d6bf0445 --- /dev/null +++ b/arch/mips/bcm63xx/dev-uart.c @@ -0,0 +1,77 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2008 Maxime Bizon + */ + +#include +#include +#include +#include +#include + +static struct resource uart0_resources[] = { + { + /* start & end filled at runtime */ + .flags = IORESOURCE_MEM, + }, + { + /* start filled at runtime */ + .flags = IORESOURCE_IRQ, + }, +}; + +static struct resource uart1_resources[] = { + { + /* start & end filled at runtime */ + .flags = IORESOURCE_MEM, + }, + { + /* start filled at runtime */ + .flags = IORESOURCE_IRQ, + }, +}; + +static struct platform_device bcm63xx_uart_devices[] = { + { + .name = "bcm63xx_uart", + .id = 0, + .num_resources = ARRAY_SIZE(uart0_resources), + .resource = uart0_resources, + }, + + { + .name = "bcm63xx_uart", + .id = 1, + .num_resources = ARRAY_SIZE(uart1_resources), + .resource = uart1_resources, + } +}; + +int __init bcm63xx_uart_register(unsigned int id) +{ + if (id >= ARRAY_SIZE(bcm63xx_uart_devices)) + return -ENODEV; + + if (id == 1 && (!BCMCPU_IS_3368() && !BCMCPU_IS_6358() && + !BCMCPU_IS_6368())) + return -ENODEV; + + if (id == 0) { + uart0_resources[0].start = bcm63xx_regset_address(RSET_UART0); + uart0_resources[0].end = uart0_resources[0].start + + RSET_UART_SIZE - 1; + uart0_resources[1].start = bcm63xx_get_irq_number(IRQ_UART0); + } + + if (id == 1) { + uart1_resources[0].start = bcm63xx_regset_address(RSET_UART1); + uart1_resources[0].end = uart1_resources[0].start + + RSET_UART_SIZE - 1; + uart1_resources[1].start = bcm63xx_get_irq_number(IRQ_UART1); + } + + return platform_device_register(&bcm63xx_uart_devices[id]); +} -- cgit v1.3.1