diff options
author | Herbert Xu <herbert@gondor.apana.org.au> | 2018-12-14 13:44:14 +0800 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2020-03-28 21:42:55 +0000 |
commit | 2993257551260450b6471d0650bec6e859cafed4 (patch) | |
tree | 9692fb6f3661b7dd40b775aa9fa64b6e9bb86030 | |
parent | 5c65fe97c9c00feb5ed10598dcd51ef7399be7ff (diff) | |
download | klibc-2993257551260450b6471d0650bec6e859cafed4.tar.gz |
[klibc] dash: eval: avoid leaking memory associated with redirections
[ dash commit 2bc6caace3b08024955ed57fc993d91067f883a1 ]
The following constructs result in ever-increasing memory usage:
while true; do { true; } </dev/null; done
while true; do ( true; ) </dev/null; done
For comparison, bash displays static memory usage in both cases.
This issue was reported for BusyBox ash which is derived from dash:
https://bugs.busybox.net/show_bug.cgi?id=7748
Signed-off-by: Ron Yorston <rmy@frippery.org>
I have simplified evaltree so that it simply sets the stack mark
unconditionally. This allows us to remove the stack marks in the
functions called by evaltree.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r-- | usr/dash/eval.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/usr/dash/eval.c b/usr/dash/eval.c index 5074aa94344c8..bba0e7f88ea4b 100644 --- a/usr/dash/eval.c +++ b/usr/dash/eval.c @@ -200,8 +200,12 @@ evaltree(union node *n, int flags) { int checkexit = 0; int (*evalfn)(union node *, int); + struct stackmark smark; unsigned isor; int status = 0; + + setstackmark(&smark); + if (n == NULL) { TRACE(("evaltree(NULL) called\n")); goto out; @@ -317,6 +321,8 @@ exexit: exraise(EXEXIT); } + popstackmark(&smark); + return exitstatus; } @@ -396,14 +402,12 @@ evalfor(union node *n, int flags) struct arglist arglist; union node *argp; struct strlist *sp; - struct stackmark smark; int status; errlinno = lineno = n->nfor.linno; if (funcline) lineno -= funcline - 1; - setstackmark(&smark); arglist.lastp = &arglist.list; for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); @@ -420,7 +424,6 @@ evalfor(union node *n, int flags) break; } loopnest--; - popstackmark(&smark); return status; } @@ -433,14 +436,12 @@ evalcase(union node *n, int flags) union node *cp; union node *patp; struct arglist arglist; - struct stackmark smark; int status = 0; errlinno = lineno = n->ncase.linno; if (funcline) lineno -= funcline - 1; - setstackmark(&smark); arglist.lastp = &arglist.list; expandarg(n->ncase.expr, &arglist, EXP_TILDE); for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { @@ -459,8 +460,6 @@ evalcase(union node *n, int flags) } } out: - popstackmark(&smark); - return status; } @@ -717,7 +716,6 @@ evalcommand(union node *cmd, int flags) struct localvar_list *localvar_stop; struct parsefile *file_stop; struct redirtab *redir_stop; - struct stackmark smark; union node *argp; struct arglist arglist; struct arglist varlist; @@ -746,7 +744,6 @@ evalcommand(union node *cmd, int flags) /* First expand the arguments. */ TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags)); - setstackmark(&smark); file_stop = parsefile; back_exitstatus = 0; @@ -925,7 +922,6 @@ out: * However I implemented that within libedit itself. */ setvar("_", lastarg, 0); - popstackmark(&smark); return status; } |