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@xxxxxxxxx>
---
I don't have this hardware, but this patch should not introduce any bugs
that weren't there in the original.
v2: If the strlcpy() strings aren't NULL terminated then bail out
earlier. Add a better commit message. The first commit message
sucked. Sorry for that.
diff --git a/drivers/isdn/sc/interrupt.c b/drivers/isdn/sc/interrupt.c
index 485be8b..f0225bc 100644
--- a/drivers/isdn/sc/interrupt.c
+++ b/drivers/isdn/sc/interrupt.c
@@ -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;
}
--
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