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/mem.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 tools/perf/tests/mem.c (limited to 'tools/perf/tests/mem.c') diff --git a/tools/perf/tests/mem.c b/tools/perf/tests/mem.c new file mode 100644 index 000000000..cb3d749e1 --- /dev/null +++ b/tools/perf/tests/mem.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "util/map_symbol.h" +#include "util/mem-events.h" +#include "util/mem-info.h" +#include "util/symbol.h" +#include "linux/perf_event.h" +#include "util/debug.h" +#include "tests.h" +#include + +static int check(union perf_mem_data_src data_src, + const char *string) +{ + char out[100]; + char failure[100]; + struct mem_info *mi = mem_info__new(); + int n; + + TEST_ASSERT_VAL("Memory allocation failed", mi); + *mem_info__data_src(mi) = data_src; + n = perf_mem__snp_scnprintf(out, sizeof out, mi); + n += perf_mem__lvl_scnprintf(out + n, sizeof out - n, mi); + mem_info__put(mi); + scnprintf(failure, sizeof failure, "unexpected %s", out); + TEST_ASSERT_VAL(failure, !strcmp(string, out)); + return 0; +} + +static int test__mem(struct test_suite *text __maybe_unused, int subtest __maybe_unused) +{ + int ret = 0; + union perf_mem_data_src src; + + memset(&src, 0, sizeof(src)); + + src.mem_lvl = PERF_MEM_LVL_HIT; + src.mem_lvl_num = 4; + + ret |= check(src, "N/AL4 hit"); + + src.mem_remote = 1; + + ret |= check(src, "N/ARemote L4 hit"); + + src.mem_lvl = PERF_MEM_LVL_MISS; + src.mem_lvl_num = PERF_MEM_LVLNUM_PMEM; + src.mem_remote = 0; + + ret |= check(src, "N/APMEM miss"); + + src.mem_remote = 1; + + ret |= check(src, "N/ARemote PMEM miss"); + + src.mem_snoopx = PERF_MEM_SNOOPX_FWD; + src.mem_lvl_num = PERF_MEM_LVLNUM_RAM; + + ret |= check(src , "FwdRemote RAM miss"); + + return ret; +} + +DEFINE_SUITE("Test data source output", mem); -- cgit v1.3.1