From: Eric Biggers <ebiggers3@gmail.com>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH] syscalls/keyctl05: new test for key_update() crash
Date: Mon, 31 Jul 2017 14:09:54 -0700 [thread overview]
Message-ID: <20170731210954.GB41369@gmail.com> (raw)
In-Reply-To: <87lgn5gezv.fsf@our.domain.is.not.set>
On Mon, Jul 31, 2017 at 10:57:56AM +0200, Richard Palethorpe wrote:
> > + for (i = 0; i < 10000; i++) {
> > + TEST(tst_syscall(__NR_keyctl, KEYCTL_UPDATE, keyid,
> > + payload, sizeof(payload)));
> > + if (TEST_RETURN < 0 && TEST_ERRNO != EACCES) {
> > + tst_res(TFAIL | TTERRNO, "failed to update 'user' key");
> > + return;
> > + }
> > + }
>
> There is a library for causing race conditions (tst_fuzzy_sync.h), but
> it only works with threads at the moment. I'm not entirely sure whether
> to ask you to use it or not at this stage. How reliable is the test at
> crashing a vulnerable system currently?
>
It happens either very reliably or not at all, depending on how the kernel stack
is laid out which the test has no control over. And if it *can* happen, it
doesn't need any fancy synchronization to trigger the crash.
(Also this test could use threads; it just seemed that forking was simpler.)
Eric
next prev parent reply other threads:[~2017-07-31 21:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-29 1:07 [LTP] [PATCH] syscalls/keyctl05: new test for key_update() crash Eric Biggers
2017-07-31 8:57 ` Richard Palethorpe
2017-07-31 21:09 ` Eric Biggers [this message]
2017-08-01 14:32 ` Richard Palethorpe
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