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 --- tools/perf/tests/genelf.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 tools/perf/tests/genelf.c (limited to 'tools/perf/tests/genelf.c') diff --git a/tools/perf/tests/genelf.c b/tools/perf/tests/genelf.c new file mode 100644 index 000000000..95f3be1b6 --- /dev/null +++ b/tools/perf/tests/genelf.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include +#include + +#include "debug.h" +#include "tests.h" + +#ifdef HAVE_JITDUMP +#include +#include "../util/genelf.h" +#endif + +#define TEMPL "/tmp/perf-test-XXXXXX" + +static int test__jit_write_elf(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ +#ifdef HAVE_JITDUMP + static unsigned char x86_code[] = { + 0xBB, 0x2A, 0x00, 0x00, 0x00, /* movl $42, %ebx */ + 0xB8, 0x01, 0x00, 0x00, 0x00, /* movl $1, %eax */ + 0xCD, 0x80 /* int $0x80 */ + }; + char path[PATH_MAX]; + int fd, ret; + + strcpy(path, TEMPL); + + fd = mkstemp(path); + if (fd < 0) { + perror("mkstemp failed"); + return TEST_FAIL; + } + + pr_info("Writing jit code to: %s\n", path); + + ret = jit_write_elf(fd, 0, "main", x86_code, sizeof(x86_code), + NULL, 0, NULL, 0, 0); + close(fd); + + unlink(path); + + return ret ? TEST_FAIL : 0; +#else + return TEST_SKIP; +#endif +} + +DEFINE_SUITE("Test jit_write_elf", jit_write_elf); -- cgit v1.3.1