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/util/units.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 tools/perf/util/units.c (limited to 'tools/perf/util/units.c') diff --git a/tools/perf/util/units.c b/tools/perf/util/units.c new file mode 100644 index 000000000..0bbacf5a2 --- /dev/null +++ b/tools/perf/util/units.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "units.h" +#include +#include +#include +#include +#include +#include + +unsigned long parse_tag_value(const char *str, struct parse_tag *tags) +{ + struct parse_tag *i = tags; + + while (i->tag) { + const char *s = strchr(str, i->tag); + + if (s) { + unsigned long int value; + char *endptr; + + value = strtoul(str, &endptr, 10); + if (s != endptr) + break; + + if (value > ULONG_MAX / i->mult) + break; + value *= i->mult; + return value; + } + i++; + } + + return (unsigned long) -1; +} + +double convert_unit_double(double value, char *unit) +{ + *unit = ' '; + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'K'; + } + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'M'; + } + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'G'; + } + + return value; +} + +unsigned long convert_unit(unsigned long value, char *unit) +{ + double v = convert_unit_double((double)value, unit); + + return (unsigned long)v; +} + +int unit_number__scnprintf(char *buf, size_t size, u64 n) +{ + char unit[] = "BKMG"; + int i = 0; + + while (((n / 1024) > 1) && (i < 3)) { + n /= 1024; + i++; + } + + return scnprintf(buf, size, "%" PRIu64 "%c", n, unit[i]); +} -- cgit v1.3.1