diff options
Diffstat (limited to 'sys/kern/exec_subr.c')
| -rw-r--r-- | sys/kern/exec_subr.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/sys/kern/exec_subr.c b/sys/kern/exec_subr.c index 538e20ecb65..e51b6af910f 100644 --- a/sys/kern/exec_subr.c +++ b/sys/kern/exec_subr.c @@ -1,4 +1,4 @@ -/* $OpenBSD: exec_subr.c,v 1.46 2014/12/17 06:58:11 guenther Exp $ */ +/* $OpenBSD: exec_subr.c,v 1.47 2015/02/06 23:58:12 deraadt Exp $ */ /* $NetBSD: exec_subr.c,v 1.9 1994/12/04 03:10:42 mycroft Exp $ */ /* @@ -289,16 +289,28 @@ vmcmd_randomize(struct proc *p, struct exec_vmcmd *cmd) { char *buf; int error; + size_t off = 0, len; if (cmd->ev_len == 0) return (0); - if (cmd->ev_len > 1024) + if (cmd->ev_len > ELF_RANDOMIZE_LIMIT) return (EINVAL); - buf = malloc(cmd->ev_len, M_TEMP, M_WAITOK); - arc4random_buf(buf, cmd->ev_len); - error = copyout(buf, (void *)cmd->ev_addr, cmd->ev_len); - free(buf, M_TEMP, cmd->ev_len); + buf = malloc(PAGE_SIZE, M_TEMP, M_WAITOK); + len = cmd->ev_len; + do { + size_t sublen = MIN(len, PAGE_SIZE); + + arc4random_buf(buf, sublen); + error = copyout(buf, (void *)cmd->ev_addr + off, sublen); + if (error) + break; + off += sublen; + len -= sublen; + if (len) + yield(); + } while (len); + free(buf, M_TEMP, PAGE_SIZE); return (error); } |