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| author | Shivank Garg <shivankg@amd.com> | 2026-08-22 19:22:05 +0000 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2026-09-09 17:51:44 +0530 |
| commit | e873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch) | |
| tree | cc1ce1567f5b982359331863ebd9da38741f8d2e /include/uapi/asm-generic/bitsperlong.h | |
| download | linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.tar.gz linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.zip | |
dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted
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 <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'include/uapi/asm-generic/bitsperlong.h')
| -rw-r--r-- | include/uapi/asm-generic/bitsperlong.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/uapi/asm-generic/bitsperlong.h b/include/uapi/asm-generic/bitsperlong.h new file mode 100644 index 000000000..fadb3f857 --- /dev/null +++ b/include/uapi/asm-generic/bitsperlong.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI__ASM_GENERIC_BITS_PER_LONG +#define _UAPI__ASM_GENERIC_BITS_PER_LONG + +#ifndef __BITS_PER_LONG +/* + * In order to keep safe and avoid regression, only unify uapi + * bitsperlong.h for some archs which are using newer toolchains + * that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__. + * See the following link for more info: + * https://lore.kernel.org/linux-arch/b9624545-2c80-49a1-ac3c-39264a591f7b@app.fastmail.com/ + */ +#if defined(__CHAR_BIT__) && defined(__SIZEOF_LONG__) +#define __BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__) +#else +/* + * There seems to be no way of detecting this automatically from user + * space, so 64 bit architectures should override this in their + * bitsperlong.h. In particular, an architecture that supports + * both 32 and 64 bit user space must not rely on CONFIG_64BIT + * to decide it, but rather check a compiler provided macro. + */ +#define __BITS_PER_LONG 32 +#endif +#endif + +#ifndef __BITS_PER_LONG_LONG +#define __BITS_PER_LONG_LONG 64 +#endif + +#endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */ |