Assertion `addr < cache->len && 2 <= cache->len - addr' in virtio-blk
This bug has been copied automatically from: https://bugs.launchpad.net/qemu/+bug/1910941
Reported by 'Cheolwoo,Myung' on 2021-01-11 :
Hello, Using hypervisor fuzzer, hyfuzz, I found an assertion failure through virtio-blk emulator. A malicious guest user/process could use this flaw to abort the QEMU process on the host, resulting in a denial of service. This was found in version 5.2.0 (master) ``` qemu-system-i386: /home/cwmyung/prj/hyfuzz/src/qemu- master/include/exec/memory_ldst_cached.h.inc:88: void address_space_stw_le_cached(MemoryRegionCache *, hwaddr, uint32_t, MemTxAttrs, MemTxResult *): Assertion `addr < cache->len && 2 <= cache->len - addr' failed. [1] 1877 abort (core dumped) /home/cwmyung/prj/hyfuzz/src/qemu- master/build/i386-softmmu/qemu-system-i386 Program terminated with signal SIGABRT, Aborted. #0 0x00007f71cc171f47 in __GI_raise (sig=sig@entry=0x6) at ../sysdeps/unix/sysv/linux/raise.c:51 #1 0x00007f71cc1738b1 in __GI_abort () at abort.c:79 #2 0x00007f71cc16342a in __assert_fail_base (fmt=0x7f71cc2eaa38 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x56537b324230 "addr < cache->len && 2 <= cache->len - addr", file=file@entry=0x56537b32425c "/home/cwmyung/prj/hyfuzz/src/qemu- master/include/exec/memory_ldst_cached.h.inc", line=line@entry=0x58, function=function@entry=0x56537b3242ab "void address_space_stw_le_cached(MemoryRegionCache *, hwaddr, uint32_t, MemTxAttrs, MemTxResult *)") at assert.c:92 #3 0x00007f71cc1634a2 in __GI___assert_fail (assertion=0x56537b324230 "addr < cache->len && 2 <= cache->len - addr", file=0x56537b32425c "/home/cwmyung/prj/hyfuzz/src/qemu- master/include/exec/memory_ldst_cached.h.inc", line=0x58, function=0x56537b3242ab "void address_space_stw_le_cached(MemoryRegionCache *, hwaddr, uint32_t, MemTxAttrs, MemTxResult *)") at assert.c:101 #4 0x000056537af3c917 in address_space_stw_le_cached (attrs=..., result=<optimized out>, cache=<optimized out>, addr=<optimized out>, val=<optimized out>) at /home/cwmyung/prj/hyfuzz/src/qemu- master/include/exec/memory_ldst_cached.h.inc:88 #5 0x000056537af3c917 in stw_le_phys_cached (cache=<optimized out>, addr=<optimized out>, val=<optimized out>) at /home/cwmyung/prj/hyfuzz/src/qemu- master/include/exec/memory_ldst_phys.h.inc:121 #6 0x000056537af3c917 in virtio_stw_phys_cached (vdev=<optimized out>, cache=<optimized out>, pa=<optimized out>, value=<optimized out>) at /home/cwmyung/prj/hyfuzz/src/qemu-master/include/hw/virtio/virtio- access.h:196 #7 0x000056537af2b809 in vring_set_avail_event (vq=<optimized out>, val=0x0) at ../hw/virtio/virtio.c:429 #8 0x000056537af2b809 in virtio_queue_split_set_notification (vq=<optimized out>, enable=<optimized out>) at ../hw/virtio/virtio.c:438 #9 0x000056537af2b809 in virtio_queue_set_notification (vq=<optimized out>, enable=0x1) at ../hw/virtio/virtio.c:499 #10 0x000056537b07ce1c in virtio_blk_handle_vq (s=0x56537d6bb3a0, vq=0x56537d6c0680) at ../hw/block/virtio-blk.c:795 #11 0x000056537af3eb4d in virtio_queue_notify_aio_vq (vq=0x56537d6c0680) at ../hw/virtio/virtio.c:2326 #12 0x000056537af3ba04 in virtio_queue_host_notifier_aio_read (n=<optimized out>) at ../hw/virtio/virtio.c:3533 #13 0x000056537b20901c in aio_dispatch_handler (ctx=0x56537c4179f0, node=0x7f71a810b370) at ../util/aio-posix.c:329 #14 0x000056537b20838c in aio_dispatch_handlers (ctx=<optimized out>) at ../util/aio-posix.c:372 #15 0x000056537b20838c in aio_dispatch (ctx=0x56537c4179f0) at ../util/aio-posix.c:382 #16 0x000056537b1f99cb in aio_ctx_dispatch (source=0x2, callback=0x7ffc8add9f90, user_data=0x0) at ../util/async.c:306 #17 0x00007f71d1c10417 in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #18 0x000056537b1f1bab in glib_pollfds_poll () at ../util/main-loop.c:232 #19 0x000056537b1f1bab in os_host_main_loop_wait (timeout=<optimized out>) at ../util/main-loop.c:255 #20 0x000056537b1f1bab in main_loop_wait (nonblocking=<optimized out>) at ../util/main-loop.c:531 #21 0x000056537af879d7 in qemu_main_loop () at ../softmmu/runstate.c:720 #22 0x000056537a928a3b in main (argc=<optimized out>, argc@entry=0x15, argv=<optimized out>, argv@entry=0x7ffc8adda718, envp=<optimized out>) at ../softmmu/main.c:50 #23 0x00007f71cc154b97 in __libc_start_main (main=0x56537a928a30 <main>, argc=0x15, argv=0x7ffc8adda718, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffc8adda708) at ../csu/libc- start.c:310 #24 0x000056537a92894a in _start () ``` To reproduce this issue, please run the QEMU with the following command line. ``` # To reproduce this issue, please run the QEMU process with the following command line. $ qemu-system-i386 -m 512 -drive file=hyfuzz.img,index=0,media=disk,format=raw -device virtio-blk- pci,drive=drive0,id=virtblk0,num-queues=4 -drive file=disk.img,if=none,id=drive0 ``` Please let me know if I can provide any further info. Thank you.