Thank you both for the reproducers. Please see the proposed patchset here: https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg06063.html
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1919036 Title: Assertion failure in fifo8_push_all() through am53c974 Status in QEMU: New Bug description: Hello, Using hypervisor fuzzer, hyfuzz, I found an assertion failure through am53c974 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, 3f8d1885e4) ``` qemu-system-i386: ../util/fifo8.c:43: fifo8_push_all: Assertion `fifo->num + num <= fifo->capacity' failed. #0 0x00007ffff0218fb7 in __GI_raise (sig=sig@entry=0x6) at ../sysdeps/unix/sysv/linux/raise.c:51 #1 0x00007ffff021a921 in __GI_abort () at abort.c:79 #2 0x00007ffff020a48a in __assert_fail_base (fmt=0x7ffff0391750 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x555558ed2400 "fifo->num + num <= fifo->capacity", file=file@entry=0x555558ed2380 "../util/fifo8.c", line=line@entry=0x2b, function=function@entry=0x555558ed2560 <__PRETTY_FUNCTION__.16583> "fifo8_push_all") at assert.c:92 #3 0x00007ffff020a502 in __GI___assert_fail (assertion=assertion@entry=0x555558ed2400 "fifo->num + num <= fifo->capacity", file=file@entry=0x555558ed2380 "../util/fifo8.c", line=line@entry=0x2b, function=function@entry=0x555558ed2560 <__PRETTY_FUNCTION__.16583> "fifo8_push_all") at assert.c:101 #4 0x00005555587749c4 in fifo8_push_all (fifo=fifo@entry=0x61f000005200, data=data@entry=0x7fff72bfa640 "", num=num@entry=0x24) at ../util/fifo8.c:43 #5 0x00005555572bd13e in esp_do_dma (s=s@entry=0x61f000005088) at ../hw/scsi/esp.c:577 #6 0x00005555572bfc8f in handle_ti (s=0x61f000005088) at ../hw/scsi/esp.c:845 #7 0x00005555572c419c in esp_reg_write (s=0x61f000005088, saddr=saddr@entry=0x3, val=<optimized out>) at ../hw/scsi/esp.c:987 #8 0x0000555557bb916a in esp_pci_io_write (opaque=0x61f000004680, addr=<optimized out>, val=<optimized out>, size=<optimized out>) at ../hw/scsi/esp-pci.c:214 #9 0x000055555817ea28 in memory_region_write_accessor (mr=0x61f000004f70, addr=<optimized out>, value=<optimized out>, size=<optimized out>, shift=<optimized out>, mask=<optimized out>, attrs=...) at ../softmmu/memory.c:491 #10 0x0000555558176671 in access_with_adjusted_size (addr=addr@entry=0xc, value=value@entry=0x7fff72bfb2a8, size=size@entry=0x1, access_size_min=<optimized out>, access_size_max=<optimized out>, access_fn= 0x55555817e7c0 <memory_region_write_accessor>, mr=0x61f000004f70, attrs=...) at ../softmmu/memory.c:552 #11 0x00005555581892aa in memory_region_dispatch_write (mr=mr@entry=0x61f000004f70, addr=<optimized out>, data=<optimized out>, data@entry=0xffffff90, op=op@entry=MO_8, attrs=..., attrs@entry=...) at ../softmmu/memory.c:1508 #12 0x0000555558024b66 in address_space_stb (as=<optimized out>, addr=<optimized out>, val=<optimized out>, attrs=..., result=0x0) at /home/cwmyung/prj/hyfuzz/src/qemu-master/memory_ldst.c.inc:382 #13 0x00007fff9323641c in code_gen_buffer () #14 0x0000555557e793bb in cpu_tb_exec (tb_exit=<optimized out>, itb=<optimized out>, cpu=0x62e0000004b4) at ../accel/tcg/cpu-exec.c:190 #15 0x0000555557e793bb in cpu_loop_exec_tb (tb_exit=<optimized out>, last_tb=<optimized out>, tb=<optimized out>, cpu=0x62e0000004b4) at ../accel/tcg/cpu-exec.c:673 #16 0x0000555557e793bb in cpu_exec (cpu=cpu@entry=0x62e000000400) at ../accel/tcg/cpu-exec.c:798 #17 0x0000555557f5fc5a in tcg_cpus_exec (cpu=cpu@entry=0x62e000000400) at ../accel/tcg/tcg-accel-ops.c:68 #18 0x00005555582260af in mttcg_cpu_thread_fn (arg=arg@entry=0x62e000000400) at ../accel/tcg/tcg-accel-ops-mttcg.c:70 #19 0x0000555558777b05 in qemu_thread_start (args=<optimized out>) at ../util/qemu-thread-posix.c:521 #20 0x00007ffff05d26db in start_thread (arg=0x7fff72bff700) at pthread_create.c:463 #21 0x00007ffff02fb71f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 ``` To reproduce the assertion failure, please run the QEMU with the following command line. ``` $ ./qemu-system-i386 -m 512 -drive file=./hyfuzz.img,index=0,media=disk,format=raw -device am53c974,id=scsi -device scsi-hd,drive=SysDisk -drive id=SysDisk,if=none,file=./disk.img ``` Please let me know if I can provide any further info. Thank you. - Cheolwoo, Myung (Seoul National University) To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1919036/+subscriptions
