On Sun, Jun 21, 2020 at 02:23:54AM +0200, Jeremie Courreges-Anglas wrote:
>
> Small bug, but still...
>
> naddy@ reported a double free when interrupting (^C) ftp(1) at the end
> or url_get(). If that happens, the SIGINT handler longjmps and the
> cleanup path is taken a second time. To avoid this, restore the
> previous SIGINT handler in each possible error path. I chose to restore
> it earlier in the successful path to avoid too much duplication.
> file_get() gets the same treatment.
>
> Note that naddy hit this because of another bug causing ftp_close()
> to stall, and this depends on the server you're talking to. You can
> insert a sleep(10); call before "return (rval);" to help reproduce the
> crash.
>
> ok?
>
ok tb
>
> Index: fetch.c
> ===
> RCS file: /d/cvs/src/usr.bin/ftp/fetch.c,v
> retrieving revision 1.195
> diff -u -p -p -u -r1.195 fetch.c
> --- fetch.c 20 Jun 2020 09:59:48 - 1.195
> +++ fetch.c 21 Jun 2020 00:12:10 -
> @@ -261,6 +261,7 @@ file_get(const char *path, const char *o
> for (cp = buf; len > 0; len -= wlen, cp += wlen) {
> if ((wlen = write(out, cp, len)) == -1) {
> warn("Writing %s", savefile);
> + signal(SIGINT, oldintr);
> signal(SIGINFO, oldinti);
> goto cleanup_copy;
> }
> @@ -274,6 +275,7 @@ file_get(const char *path, const char *o
> }
> }
> save_errno = errno;
> + signal(SIGINT, oldintr);
> signal(SIGINFO, oldinti);
> if (hash && !progress && bytes > 0) {
> if (bytes < mark)
> @@ -288,7 +290,6 @@ file_get(const char *path, const char *o
> progressmeter(1, NULL);
> if (verbose)
> ptransfer(0);
> - (void)signal(SIGINT, oldintr);
>
> rval = 0;
>
> @@ -1032,6 +1033,7 @@ noslash:
> oldinti = signal(SIGINFO, psummary);
> if (chunked) {
> error = save_chunked(fin, tls, out, buf, buflen);
> + signal(SIGINT, oldintr);
> signal(SIGINFO, oldinti);
> if (error == -1)
> goto cleanup_url_get;
> @@ -1041,6 +1043,7 @@ noslash:
> for (cp = buf; len > 0; len -= wlen, cp += wlen) {
> if ((wlen = write(out, cp, len)) == -1) {
> warn("Writing %s", savefile);
> + signal(SIGINT, oldintr);
> signal(SIGINFO, oldinti);
> goto cleanup_url_get;
> }
> @@ -1054,6 +1057,7 @@ noslash:
> }
> }
> save_errno = errno;
> + signal(SIGINT, oldintr);
> signal(SIGINFO, oldinti);
> if (hash && !progress && bytes > 0) {
> if (bytes < mark)
> @@ -1080,7 +1084,6 @@ noslash:
>
> if (verbose)
> ptransfer(0);
> - (void)signal(SIGINT, oldintr);
>
> rval = 0;
> goto cleanup_url_get;
>
>
> --
> jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
>
