accel/tcg/translate-all.c:2511: page_check_range: Assertion `start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)' failed.

[Serge Belyshev]

qemu-riscv64 version 2.12.93 crashes when mincore() is called with invalid pointer with the following message:

qemu-riscv64: /opt/qemu/accel/tcg/translate-all.c:2511: page_check_range: Assertion `start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)' failed.
qemu:handle_cpu_signal received signal outside vCPU context @ pc=0x600014ef

Testcase:

#include <sys/mman.h>

int main (void)
{
  unsigned char v;
  return mincore ((void *) 0x00000010000000000, 1, &v);
}

Backtrace:

#0 raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x000000006000140a in abort () at abort.c:79
#2 0x00000000600012ec in __assert_fail_base (
    fmt=0x6024eae8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",
    assertion=0x601b9758 "start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)",
    file=0x601b9658 "/opt/qemu/accel/tcg/translate-all.c", line=2511,
    function=0x601b9810 <__PRETTY_FUNCTION__.23867> "page_check_range") at assert.c:92
#3 0x000000006010e10e in __assert_fail (
    assertion=assertion@entry=0x601b9758 "start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)", file=file@entry=0x601b9658 "/opt/qemu/accel/tcg/translate-all.c", line=line@entry=2511,
    function=function@entry=0x601b9810 <__PRETTY_FUNCTION__.23867> "page_check_range")
    at assert.c:101
#4 0x000000006003e916 in page_check_range (start=start@entry=1099511627776, len=len@entry=1,
    flags=flags@entry=1) at /opt/qemu/accel/tcg/translate-all.c:2511
#5 0x0000000060057717 in access_ok (size=1, addr=1099511627776, type=0)
    at /opt/qemu/linux-user/qemu.h:567
#6 lock_user (copy=0, len=1, guest_addr=1099511627776, type=0)
    at /opt/qemu/linux-user/qemu.h:567
#7 do_syscall (cpu_env=cpu_env@entry=0x622fca28, num=232, arg1=1099511627776, arg2=1,
    arg3=274886298751, arg4=0, arg5=274886298808, arg6=66518, arg7=0, arg8=0)
    at /opt/qemu/linux-user/syscall.c:11635
#8 0x0000000060066c5c in cpu_loop (env=env@entry=0x622fca28)
    at /opt/qemu/linux-user/riscv/cpu_loop.c:55
#9 0x0000000060002156 in main (argc=<optimized out>, argv=0x7fffffffed68,
    envp=<optimized out>) at /opt/qemu/linux-user/main.c:819

[Serge Belyshev (belyshev)]

Fixed by 0acd4ab849827bbc20402e01c9da088207c0d236 ("linux-user: check valid address in access_ok()"), fix released in v5.0.0.