[PATCH 4.2.y-ckt 116/305] isdn: Partially revert debug format string usage clean up

From: Kamal Mostafa
Date: Fri Jan 15 2016 - 20:02:08 EST


4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Christoph Biedl <linux-kernel.bfrz@xxxxxxxxxxxxxxxxxx>

commit 19cebbcb04c8277bb8a7905957c8af11967c4e28 upstream.

Commit 35a4a57 ("isdn: clean up debug format string usage") introduced
a safeguard to avoid accidential format string interpolation of data
when calling debugl1 or HiSax_putstatus. This did however not take into
account VHiSax_putstatus (called by HiSax_putstatus) does *not* call
vsprintf if the head parameter is NULL - the format string is treated
as plain text then instead. As a result, the string "%s" is processed
literally, and the actual information is lost. This affects the isdnlog
userspace program which stopped logging information since that commit.

So revert the HiSax_putstatus invocations to the previous state.

Fixes: 35a4a5733b0a ("isdn: clean up debug format string usage")
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Karsten Keil <isdn@xxxxxxxxxxxxxx>
Signed-off-by: Christoph Biedl <linux-kernel.bfrz@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/isdn/hisax/config.c | 2 +-
drivers/isdn/hisax/hfc_pci.c | 2 +-
drivers/isdn/hisax/hfc_sx.c | 2 +-
drivers/isdn/hisax/q931.c | 6 +++---
4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/isdn/hisax/config.c b/drivers/isdn/hisax/config.c
index b33f53b..bf04d2a 100644
--- a/drivers/isdn/hisax/config.c
+++ b/drivers/isdn/hisax/config.c
@@ -1896,7 +1896,7 @@ static void EChannel_proc_rcv(struct hisax_d_if *d_if)
ptr--;
*ptr++ = '\n';
*ptr = 0;
- HiSax_putstatus(cs, NULL, "%s", cs->dlog);
+ HiSax_putstatus(cs, NULL, cs->dlog);
} else
HiSax_putstatus(cs, "LogEcho: ",
"warning Frame too big (%d)",
diff --git a/drivers/isdn/hisax/hfc_pci.c b/drivers/isdn/hisax/hfc_pci.c
index 4a48255..90449e1 100644
--- a/drivers/isdn/hisax/hfc_pci.c
+++ b/drivers/isdn/hisax/hfc_pci.c
@@ -901,7 +901,7 @@ Begin:
ptr--;
*ptr++ = '\n';
*ptr = 0;
- HiSax_putstatus(cs, NULL, "%s", cs->dlog);
+ HiSax_putstatus(cs, NULL, cs->dlog);
} else
HiSax_putstatus(cs, "LogEcho: ", "warning Frame too big (%d)", total - 3);
}
diff --git a/drivers/isdn/hisax/hfc_sx.c b/drivers/isdn/hisax/hfc_sx.c
index b1fad81..13b2151 100644
--- a/drivers/isdn/hisax/hfc_sx.c
+++ b/drivers/isdn/hisax/hfc_sx.c
@@ -674,7 +674,7 @@ receive_emsg(struct IsdnCardState *cs)
ptr--;
*ptr++ = '\n';
*ptr = 0;
- HiSax_putstatus(cs, NULL, "%s", cs->dlog);
+ HiSax_putstatus(cs, NULL, cs->dlog);
} else
HiSax_putstatus(cs, "LogEcho: ", "warning Frame too big (%d)", skb->len);
}
diff --git a/drivers/isdn/hisax/q931.c b/drivers/isdn/hisax/q931.c
index b420f8b..ba4beb2 100644
--- a/drivers/isdn/hisax/q931.c
+++ b/drivers/isdn/hisax/q931.c
@@ -1179,7 +1179,7 @@ LogFrame(struct IsdnCardState *cs, u_char *buf, int size)
dp--;
*dp++ = '\n';
*dp = 0;
- HiSax_putstatus(cs, NULL, "%s", cs->dlog);
+ HiSax_putstatus(cs, NULL, cs->dlog);
} else
HiSax_putstatus(cs, "LogFrame: ", "warning Frame too big (%d)", size);
}
@@ -1246,7 +1246,7 @@ dlogframe(struct IsdnCardState *cs, struct sk_buff *skb, int dir)
}
if (finish) {
*dp = 0;
- HiSax_putstatus(cs, NULL, "%s", cs->dlog);
+ HiSax_putstatus(cs, NULL, cs->dlog);
return;
}
if ((0xfe & buf[0]) == PROTO_DIS_N0) { /* 1TR6 */
@@ -1509,5 +1509,5 @@ dlogframe(struct IsdnCardState *cs, struct sk_buff *skb, int dir)
dp += sprintf(dp, "Unknown protocol %x!", buf[0]);
}
*dp = 0;
- HiSax_putstatus(cs, NULL, "%s", cs->dlog);
+ HiSax_putstatus(cs, NULL, cs->dlog);
}
--
1.9.1