linux-user: allocate heap memory for execve arguments

Arguments passed to execve(2) call from user program could
be large, allocating stack memory for them via alloca(3) call
would lead to bad behaviour. Use 'g_new0' to allocate memory
for such arguments.

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
Prasad J Pandit 2017-03-07 12:51:47 +05:30 committed by Riku Voipio
parent c4e316cfb5
commit b936cb50aa

View File

@ -7985,8 +7985,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
envc++;
}
argp = alloca((argc + 1) * sizeof(void *));
envp = alloca((envc + 1) * sizeof(void *));
argp = g_new0(char *, argc + 1);
envp = g_new0(char *, envc + 1);
for (gp = guest_argp, q = argp; gp;
gp += sizeof(abi_ulong), q++) {
@ -8047,6 +8047,9 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
break;
unlock_user(*q, addr, 0);
}
g_free(argp);
g_free(envp);
}
break;
case TARGET_NR_chdir: