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authorDan Carpenter <dan.carpenter@oracle.com>2013-01-24 20:40:56 +0000
committerDavid S. Miller <davem@davemloft.net>2013-01-27 20:38:19 -0500
commit4bf613c6d87399e3c8a4d5e14281456b6959d8fd (patch)
tree6bdbb94f2d769c6c3b401a787d9f9f7f56ff3963 /net/irda/irnet
parent6efecd8c51c0118038495a5e10a0d855938da9ad (diff)
downloadlinux-4bf613c6d87399e3c8a4d5e14281456b6959d8fd.tar.gz
irda: buffer overflow in irnet_ctrl_read()
The comments here say that the /* Max event is 61 char */ but in 2003 we changed the event format and now the max event size is 75. The longest event is: "Discovered %08x (%s) behind %08x {hints %02X-%02X}\n", 12345678901 23 456789012 34567890 1 2 3 +8 +21 +8 +2 +2 +1 = 75 characters. There was a check to return -EOVERFLOW if the user gave us a "count" value that was less than 64. Raising it to 75 might break backwards compatability. Instead I removed the check and now it returns a truncated string if "count" is too low. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/irda/irnet')
-rw-r--r--net/irda/irnet/irnet_ppp.c117
1 files changed, 58 insertions, 59 deletions
diff --git a/net/irda/irnet/irnet_ppp.c b/net/irda/irnet/irnet_ppp.c
index 2bb2beb6a37..3c83a1e5ab0 100644
--- a/net/irda/irnet/irnet_ppp.c
+++ b/net/irda/irnet/irnet_ppp.c
@@ -214,8 +214,7 @@ irnet_get_discovery_log(irnet_socket * ap)
* After reading : discoveries = NULL ; disco_index = Y ; disco_number = -1
*/
static inline int
-irnet_read_discovery_log(irnet_socket * ap,
- char * event)
+irnet_read_discovery_log(irnet_socket *ap, char *event, int buf_size)
{
int done_event = 0;
@@ -237,12 +236,13 @@ irnet_read_discovery_log(irnet_socket * ap,
if(ap->disco_index < ap->disco_number)
{
/* Write an event */
- sprintf(event, "Found %08x (%s) behind %08x {hints %02X-%02X}\n",
- ap->discoveries[ap->disco_index].daddr,
- ap->discoveries[ap->disco_index].info,
- ap->discoveries[ap->disco_index].saddr,
- ap->discoveries[ap->disco_index].hints[0],
- ap->discoveries[ap->disco_index].hints[1]);
+ snprintf(event, buf_size,
+ "Found %08x (%s) behind %08x {hints %02X-%02X}\n",
+ ap->discoveries[ap->disco_index].daddr,
+ ap->discoveries[ap->disco_index].info,
+ ap->discoveries[ap->disco_index].saddr,
+ ap->discoveries[ap->disco_index].hints[0],
+ ap->discoveries[ap->disco_index].hints[1]);
DEBUG(CTRL_INFO, "Writing discovery %d : %s\n",
ap->disco_index, ap->discoveries[ap->disco_index].info);
@@ -282,27 +282,24 @@ irnet_ctrl_read(irnet_socket * ap,
size_t count)
{
DECLARE_WAITQUEUE(wait, current);
- char event[64]; /* Max event is 61 char */
+ char event[75];
ssize_t ret = 0;
DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
- /* Check if we can write an event out in one go */
- DABORT(count < sizeof(event), -EOVERFLOW, CTRL_ERROR, "Buffer to small.\n");
-
#ifdef INITIAL_DISCOVERY
/* Check if we have read the log */
- if(irnet_read_discovery_log(ap, event))
+ if (irnet_read_discovery_log(ap, event, sizeof(event)))
{
- /* We have an event !!! Copy it to the user */
- if(copy_to_user(buf, event, strlen(event)))
+ count = min(strlen(event), count);
+ if (copy_to_user(buf, event, count))
{
DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
return -EFAULT;
}
DEXIT(CTRL_TRACE, "\n");
- return strlen(event);
+ return count;
}
#endif /* INITIAL_DISCOVERY */
@@ -339,79 +336,81 @@ irnet_ctrl_read(irnet_socket * ap,
switch(irnet_events.log[ap->event_index].event)
{
case IRNET_DISCOVER:
- sprintf(event, "Discovered %08x (%s) behind %08x {hints %02X-%02X}\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].saddr,
- irnet_events.log[ap->event_index].hints.byte[0],
- irnet_events.log[ap->event_index].hints.byte[1]);
+ snprintf(event, sizeof(event),
+ "Discovered %08x (%s) behind %08x {hints %02X-%02X}\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].saddr,
+ irnet_events.log[ap->event_index].hints.byte[0],
+ irnet_events.log[ap->event_index].hints.byte[1]);
break;
case IRNET_EXPIRE:
- sprintf(event, "Expired %08x (%s) behind %08x {hints %02X-%02X}\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].saddr,
- irnet_events.log[ap->event_index].hints.byte[0],
- irnet_events.log[ap->event_index].hints.byte[1]);
+ snprintf(event, sizeof(event),
+ "Expired %08x (%s) behind %08x {hints %02X-%02X}\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].saddr,
+ irnet_events.log[ap->event_index].hints.byte[0],
+ irnet_events.log[ap->event_index].hints.byte[1]);
break;
case IRNET_CONNECT_TO:
- sprintf(event, "Connected to %08x (%s) on ppp%d\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].unit);
+ snprintf(event, sizeof(event), "Connected to %08x (%s) on ppp%d\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].unit);
break;
case IRNET_CONNECT_FROM:
- sprintf(event, "Connection from %08x (%s) on ppp%d\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].unit);
+ snprintf(event, sizeof(event), "Connection from %08x (%s) on ppp%d\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].unit);
break;
case IRNET_REQUEST_FROM:
- sprintf(event, "Request from %08x (%s) behind %08x\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].saddr);
+ snprintf(event, sizeof(event), "Request from %08x (%s) behind %08x\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].saddr);
break;
case IRNET_NOANSWER_FROM:
- sprintf(event, "No-answer from %08x (%s) on ppp%d\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].unit);
+ snprintf(event, sizeof(event), "No-answer from %08x (%s) on ppp%d\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].unit);
break;
case IRNET_BLOCKED_LINK:
- sprintf(event, "Blocked link with %08x (%s) on ppp%d\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].unit);
+ snprintf(event, sizeof(event), "Blocked link with %08x (%s) on ppp%d\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].unit);
break;
case IRNET_DISCONNECT_FROM:
- sprintf(event, "Disconnection from %08x (%s) on ppp%d\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name,
- irnet_events.log[ap->event_index].unit);
+ snprintf(event, sizeof(event), "Disconnection from %08x (%s) on ppp%d\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name,
+ irnet_events.log[ap->event_index].unit);
break;
case IRNET_DISCONNECT_TO:
- sprintf(event, "Disconnected to %08x (%s)\n",
- irnet_events.log[ap->event_index].daddr,
- irnet_events.log[ap->event_index].name);
+ snprintf(event, sizeof(event), "Disconnected to %08x (%s)\n",
+ irnet_events.log[ap->event_index].daddr,
+ irnet_events.log[ap->event_index].name);
break;
default:
- sprintf(event, "Bug\n");
+ snprintf(event, sizeof(event), "Bug\n");
}
/* Increment our event index */
ap->event_index = (ap->event_index + 1) % IRNET_MAX_EVENTS;
DEBUG(CTRL_INFO, "Event is :%s", event);
- /* Copy it to the user */
- if(copy_to_user(buf, event, strlen(event)))
+ count = min(strlen(event), count);
+ if (copy_to_user(buf, event, count))
{
DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
return -EFAULT;
}
DEXIT(CTRL_TRACE, "\n");
- return strlen(event);
+ return count;
}
/*------------------------------------------------------------------*/