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-flash.c | 131 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 arch/mips/bcm63xx/dev-flash.c (limited to 'arch/mips/bcm63xx/dev-flash.c') diff --git a/arch/mips/bcm63xx/dev-flash.c b/arch/mips/bcm63xx/dev-flash.c new file mode 100644 index 000000000..f9cc015d3 --- /dev/null +++ b/arch/mips/bcm63xx/dev-flash.c @@ -0,0 +1,131 @@ +/* + * Broadcom BCM63xx flash registration + * + * 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 + * Copyright (C) 2008 Florian Fainelli + * Copyright (C) 2012 Jonas Gorski + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +static struct mtd_partition mtd_partitions[] = { + { + .name = "cfe", + .offset = 0x0, + .size = 0x40000, + } +}; + +static const char *bcm63xx_part_types[] = { "bcm63xxpart", NULL }; + +static struct physmap_flash_data flash_data = { + .width = 2, + .parts = mtd_partitions, + .part_probe_types = bcm63xx_part_types, +}; + +static struct resource mtd_resources[] = { + { + .start = 0, /* filled at runtime */ + .end = 0, /* filled at runtime */ + .flags = IORESOURCE_MEM, + } +}; + +static struct platform_device mtd_dev = { + .name = "physmap-flash", + .resource = mtd_resources, + .num_resources = ARRAY_SIZE(mtd_resources), + .dev = { + .platform_data = &flash_data, + }, +}; + +static int __init bcm63xx_detect_flash_type(void) +{ + u32 val; + + switch (bcm63xx_get_cpu_id()) { + case BCM6328_CPU_ID: + val = bcm_misc_readl(MISC_STRAPBUS_6328_REG); + if (val & STRAPBUS_6328_BOOT_SEL_SERIAL) + return BCM63XX_FLASH_TYPE_SERIAL; + else + return BCM63XX_FLASH_TYPE_NAND; + case BCM6338_CPU_ID: + case BCM6345_CPU_ID: + case BCM6348_CPU_ID: + /* no way to auto detect so assume parallel */ + return BCM63XX_FLASH_TYPE_PARALLEL; + case BCM3368_CPU_ID: + case BCM6358_CPU_ID: + val = bcm_gpio_readl(GPIO_STRAPBUS_REG); + if (val & STRAPBUS_6358_BOOT_SEL_PARALLEL) + return BCM63XX_FLASH_TYPE_PARALLEL; + else + return BCM63XX_FLASH_TYPE_SERIAL; + case BCM6362_CPU_ID: + val = bcm_misc_readl(MISC_STRAPBUS_6362_REG); + if (val & STRAPBUS_6362_BOOT_SEL_SERIAL) + return BCM63XX_FLASH_TYPE_SERIAL; + else + return BCM63XX_FLASH_TYPE_NAND; + case BCM6368_CPU_ID: + val = bcm_gpio_readl(GPIO_STRAPBUS_REG); + switch (val & STRAPBUS_6368_BOOT_SEL_MASK) { + case STRAPBUS_6368_BOOT_SEL_NAND: + return BCM63XX_FLASH_TYPE_NAND; + case STRAPBUS_6368_BOOT_SEL_SERIAL: + return BCM63XX_FLASH_TYPE_SERIAL; + case STRAPBUS_6368_BOOT_SEL_PARALLEL: + return BCM63XX_FLASH_TYPE_PARALLEL; + } + fallthrough; + default: + return -EINVAL; + } +} + +int __init bcm63xx_flash_register(void) +{ + int flash_type; + u32 val; + + flash_type = bcm63xx_detect_flash_type(); + + switch (flash_type) { + case BCM63XX_FLASH_TYPE_PARALLEL: + /* read base address of boot chip select (0) */ + val = bcm_mpi_readl(MPI_CSBASE_REG(0)); + val &= MPI_CSBASE_BASE_MASK; + + mtd_resources[0].start = val; + mtd_resources[0].end = 0x1FFFFFFF; + + return platform_device_register(&mtd_dev); + case BCM63XX_FLASH_TYPE_SERIAL: + pr_warn("unsupported serial flash detected\n"); + return -ENODEV; + case BCM63XX_FLASH_TYPE_NAND: + pr_warn("unsupported NAND flash detected\n"); + return -ENODEV; + default: + pr_err("flash detection failed for BCM%x: %d\n", + bcm63xx_get_cpu_id(), flash_type); + return -ENODEV; + } +} -- cgit v1.3.1