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 --- include/asm-generic/error-injection.h | 43 +++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 include/asm-generic/error-injection.h (limited to 'include/asm-generic/error-injection.h') diff --git a/include/asm-generic/error-injection.h b/include/asm-generic/error-injection.h new file mode 100644 index 000000000..b05253f68 --- /dev/null +++ b/include/asm-generic/error-injection.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_ERROR_INJECTION_H +#define _ASM_GENERIC_ERROR_INJECTION_H + +#if defined(__KERNEL__) && !defined(__ASSEMBLY__) +enum { + EI_ETYPE_NULL, /* Return NULL if failure */ + EI_ETYPE_ERRNO, /* Return -ERRNO if failure */ + EI_ETYPE_ERRNO_NULL, /* Return -ERRNO or NULL if failure */ + EI_ETYPE_TRUE, /* Return true if failure */ +}; + +struct error_injection_entry { + unsigned long addr; + int etype; +}; + +struct pt_regs; + +#ifdef CONFIG_FUNCTION_ERROR_INJECTION +/* + * Whitelist generating macro. Specify functions which can be error-injectable + * using this macro. If you unsure what is required for the error-injectable + * functions, please read Documentation/fault-injection/fault-injection.rst + * 'Error Injectable Functions' section. + */ +#define ALLOW_ERROR_INJECTION(fname, _etype) \ +static struct error_injection_entry __used \ + __section("_error_injection_whitelist") \ + _eil_addr_##fname = { \ + .addr = (unsigned long)fname, \ + .etype = EI_ETYPE_##_etype, \ + } + +void override_function_with_return(struct pt_regs *regs); +#else +#define ALLOW_ERROR_INJECTION(fname, _etype) + +static inline void override_function_with_return(struct pt_regs *regs) { } +#endif +#endif + +#endif /* _ASM_GENERIC_ERROR_INJECTION_H */ -- cgit v1.3.1