Date: Sat, 26 Oct 2019 10:22:56 -0700 From: Cy Schubert <Cy.Schubert@cschubert.com> To: freebsd-hackers@freebsd.org Message-ID: <201910261722.x9QHMuK1000981@slippy.cwsent.com>
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Hi,
The following little test case segfaults when aslr is enabled:
#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
int
main(int argc, char *argv[])
{
struct rlimit rl;
int rc;
rl.rlim_cur = 50 * 4096;
rl.rlim_max = 50 * 4096;
rc = setrlimit(RLIMIT_STACK, &rl);
return(rc);
}
slippy# sysctl kern.elf64.aslr.enable=1
kern.elf64.aslr.enable: 0 -> 1
slippy# ./test
Segmentation fault (core dumped)
slippy# gdb test
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Reading symbols from test...
(gdb) run
Starting program: /export/home/cy/freebsd/tests/setrlimit/test
Program received signal SIGSEGV, Segmentation fault.
setrlimit () at setrlimit.S:4
4 setrlimit.S: No such file or directory.
(gdb) bt
#0 setrlimit () at setrlimit.S:4
Backtrace stopped: Cannot access memory at address 0x7fffffe372e8
(gdb)
It only occurs with aslr enabled and stack gap != 0. This isn't right.
--
Cheers,
Cy Schubert <Cy.Schubert@cschubert.com>
FreeBSD UNIX: <cy@FreeBSD.org> Web: http://www.FreeBSD.org
The need of the many outweighs the greed of the few.
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