From b7a314054eb55e3745a9409beaa5d8be5cd2d273 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 16 Apr 2014 14:25:16 +0300 Subject: isdn: icn: buffer overflow in icn_command() This buffer over was detected using static analysis: drivers/isdn/icn/icn.c:1325 icn_command() error: format string overflow. buf_size: 60 length: 98 The calculation for the length of the string is off because it assumes that the dial[] buffer holds a 50 character string, but actually it is at most 31 characters and NUL. I have removed the dial[] buffer because it isn't needed. The maximum length of the string is actually 79 characters and a NUL. I have made the cbuf[] array large enough to hold it and changed the sprintf() to an snprintf() as a further safety enhancement. Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller --- drivers/isdn/icn/icn.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/isdn/icn/icn.c b/drivers/isdn/icn/icn.c index 53d487f..6a7447c 100644 --- a/drivers/isdn/icn/icn.c +++ b/drivers/isdn/icn/icn.c @@ -1155,7 +1155,7 @@ icn_command(isdn_ctrl *c, icn_card *card) ulong a; ulong flags; int i; - char cbuf[60]; + char cbuf[80]; isdn_ctrl cmd; icn_cdef cdef; char __user *arg; @@ -1309,7 +1309,6 @@ icn_command(isdn_ctrl *c, icn_card *card) break; if ((c->arg & 255) < ICN_BCH) { char *p; - char dial[50]; char dcode[4]; a = c->arg; @@ -1321,10 +1320,10 @@ icn_command(isdn_ctrl *c, icn_card *card) } else /* Normal Dial */ strcpy(dcode, "CAL"); - strcpy(dial, p); - sprintf(cbuf, "%02d;D%s_R%s,%02d,%02d,%s\n", (int) (a + 1), - dcode, dial, c->parm.setup.si1, - c->parm.setup.si2, c->parm.setup.eazmsn); + snprintf(cbuf, sizeof(cbuf), + "%02d;D%s_R%s,%02d,%02d,%s\n", (int) (a + 1), + dcode, p, c->parm.setup.si1, + c->parm.setup.si2, c->parm.setup.eazmsn); i = icn_writecmd(cbuf, strlen(cbuf), 0, card); } break; -- cgit v1.1