From b530fb69cf54cf22768a3eabc0604d70b5c13fde Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 8 Oct 2010 10:21:22 -0700 Subject: [PATCH] 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: Dan Carpenter Signed-off-by: David S. Miller --- drivers/isdn/sc/interrupt.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/isdn/sc/interrupt.c b/drivers/isdn/sc/interrupt.c index 485be8b1e1b3..f0225bc0f267 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; } -- 2.20.1