Re: [Qemu-devel] [PATCH v2 2/2] linux-user: allocate heap memory for execve arguments

[P J P <ppandit@redhat.com>]

+-- On Mon, 6 Mar 2017, Eric Blake wrote --+
| On 03/06/2017 01:17 AM, P J P wrote:
| > 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_malloc0' to allocate memory
| > for such arguments.
| > 
| > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
| > ---
| >  linux-user/syscall.c | 7 +++++--
| >  1 file changed, 5 insertions(+), 2 deletions(-)
| 
| Is this patch alone (without 1/2) sufficient to solve the problem?  If
| so, then drop 1/2.

  Yes, it seems to fix the issue. Still I think having ARG_MAX limit would be 
good, as system exec(3) routines too impose _SC_ARG_MAX limit. I'll send a 
revised patch with 'g_try_new' call instead of g_malloc0.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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