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Commit b530fb69 authored by Dan Carpenter's avatar Dan Carpenter Committed by David S. Miller
Browse files

isdn: strcpy() => strlcpy() 



setup.phone and setup.eazmsn are 32 character buffers.
rcvmsg.msg_data.byte_array is a 48 character buffer.
sc_adapter[card]->channel[rcvmsg.phy_link_no - 1].dn is 50 chars.

The rcvmsg struct comes from the memcpy_fromio() in receivemessage().
I guess that means it's data off the wire.  I'm not very familiar with
this code but I don't see any reason to assume these strings are NULL
terminated.

Also it's weird that "dn" in a 50 character buffer but we only seem to
use 32 characters.  In drivers/isdn/sc/scioc.h, "dn" is only a 49
character buffer.  So potentially there is still an issue there.

The important thing for now is to prevent the memory corruption.

Signed-off-by: default avatarDan Carpenter <error27@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fb3dbece

drivers/isdn/sc/interrupt.c

+14 −4
Original line number Diff line number Diff line
@@ -112,11 +112,19 @@ irqreturn_t interrupt_handler(int dummy, void *card_inst) 
			}

			else if(callid>=0x0000 && callid<=0x7FFF)

			{

				int len;



				pr_debug("%s: Got Incoming Call\n",

						sc_adapter[card]->devicename);

				strcpy(setup.phone,&(rcvmsg.msg_data.byte_array[4]));

				strcpy(setup.eazmsn,

					sc_adapter[card]->channel[rcvmsg.phy_link_no-1].dn);

				len = strlcpy(setup.phone, &(rcvmsg.msg_data.byte_array[4]),

						sizeof(setup.phone));

				if (len >= sizeof(setup.phone))

					continue;

				len = strlcpy(setup.eazmsn,

						sc_adapter[card]->channel[rcvmsg.phy_link_no - 1].dn,

						sizeof(setup.eazmsn));

				if (len >= sizeof(setup.eazmsn))

					continue;

				setup.si1 = 7;

				setup.si2 = 0;

				setup.plan = 0;
@@ -176,7 +184,9 @@ irqreturn_t interrupt_handler(int dummy, void *card_inst) 
		 * Handle a GetMyNumber Rsp

		 */

		if (IS_CE_MESSAGE(rcvmsg,Call,0,GetMyNumber)){

			strcpy(sc_adapter[card]->channel[rcvmsg.phy_link_no-1].dn,rcvmsg.msg_data.byte_array);

			strlcpy(sc_adapter[card]->channel[rcvmsg.phy_link_no - 1].dn,

				rcvmsg.msg_data.byte_array,

				sizeof(rcvmsg.msg_data.byte_array));

			continue;

		}