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isdn: strcpy() => strlcpy()

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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: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Carpenter 2010-10-08 10:21:22 -07:00 committed by David S. Miller
parent fb3dbece26
commit b530fb69cf
1 changed files with 14 additions and 4 deletions
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18
drivers/isdn/sc/interrupt.c
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@ -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;
}