From: Dan Carpenter <dan.carpenter@oracle.com>
To: Philipp Reisner <philipp.reisner@linbit.com>
Cc: drbd-user@lists.linbit.com, linux-kernel@vger.kernel.org
Subject: array underflow in receive_SyncParam()?
Date: Tue, 27 Mar 2012 10:10:36 +0300 [thread overview]
Message-ID: <20120327071036.GA19008@elgon.mountain> (raw)
I had a question about the following code:
drivers/block/drbd/drbd_receiver.c
2808 if (apv == 88) {
2809 if (data_size > SHARED_SECRET_MAX) {
2810 dev_err(DEV, "verify-alg too long, "
2811 "peer wants %u, accepting only %u byte\n",
2812 data_size, SHARED_SECRET_MAX);
2813 return false;
2814 }
2815
2816 if (drbd_recv(mdev, p->verify_alg, data_size) != data_size)
2817 return false;
2818
2819 /* we expect NUL terminated string */
2820 /* but just in case someone tries to be evil */
2821 D_ASSERT(p->verify_alg[data_size-1] == 0);
2822 p->verify_alg[data_size-1] = 0;
^^^^^^^^^
Is it possible for data_size to be zero here leading to an array
underflow? We test for overflows, but I don't see any place where we
test for zero.
regards,
dan carpenter
next reply other threads:[~2012-03-27 7:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-27 7:10 Dan Carpenter [this message]
2012-03-27 11:32 ` array underflow in receive_SyncParam()? Philipp Reisner
2012-03-27 11:43 ` Dan Carpenter
2012-03-28 8:26 ` Philipp Reisner
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