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/uapi/asm-generic/resource.h | 62 +++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 include/uapi/asm-generic/resource.h (limited to 'include/uapi/asm-generic/resource.h') diff --git a/include/uapi/asm-generic/resource.h b/include/uapi/asm-generic/resource.h new file mode 100644 index 000000000..f12db7a0d --- /dev/null +++ b/include/uapi/asm-generic/resource.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI_ASM_GENERIC_RESOURCE_H +#define _UAPI_ASM_GENERIC_RESOURCE_H + +/* + * Resource limit IDs + * + * ( Compatibility detail: there are architectures that have + * a different rlimit ID order in the 5-9 range and want + * to keep that order for binary compatibility. The reasons + * are historic and all new rlimits are identical across all + * arches. If an arch has such special order for some rlimits + * then it defines them prior including asm-generic/resource.h. ) + */ + +#define RLIMIT_CPU 0 /* CPU time in sec */ +#define RLIMIT_FSIZE 1 /* Maximum filesize */ +#define RLIMIT_DATA 2 /* max data size */ +#define RLIMIT_STACK 3 /* max stack size */ +#define RLIMIT_CORE 4 /* max core file size */ + +#ifndef RLIMIT_RSS +# define RLIMIT_RSS 5 /* max resident set size */ +#endif + +#ifndef RLIMIT_NPROC +# define RLIMIT_NPROC 6 /* max number of processes */ +#endif + +#ifndef RLIMIT_NOFILE +# define RLIMIT_NOFILE 7 /* max number of open files */ +#endif + +#ifndef RLIMIT_MEMLOCK +# define RLIMIT_MEMLOCK 8 /* max locked-in-memory address space */ +#endif + +#ifndef RLIMIT_AS +# define RLIMIT_AS 9 /* address space limit */ +#endif + +#define RLIMIT_LOCKS 10 /* maximum file locks held */ +#define RLIMIT_SIGPENDING 11 /* max number of pending signals */ +#define RLIMIT_MSGQUEUE 12 /* maximum bytes in POSIX mqueues */ +#define RLIMIT_NICE 13 /* max nice prio allowed to raise to + 0-39 for nice level 19 .. -20 */ +#define RLIMIT_RTPRIO 14 /* maximum realtime priority */ +#define RLIMIT_RTTIME 15 /* timeout for RT tasks in us */ +#define RLIM_NLIMITS 16 + +/* + * SuS says limits have to be unsigned. + * Which makes a ton more sense anyway. + * + * Some architectures override this (for compatibility reasons): + */ +#ifndef RLIM_INFINITY +# define RLIM_INFINITY (~0UL) +#endif + + +#endif /* _UAPI_ASM_GENERIC_RESOURCE_H */ -- cgit v1.3.1