From 45e0b4b3d532ea67bf90701e6162f31855ab3c98 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 14 Jul 2017 14:07:00 +0200 Subject: [PATCH] isdn: divert: fix sprintf buffer overflow warning One string we pass into the cs->info buffer might be too long, as pointed out by gcc: drivers/isdn/divert/isdn_divert.c: In function 'll_callback': drivers/isdn/divert/isdn_divert.c:488:22: error: '%d' directive writing between 1 and 3 bytes into a region of size between 1 and 69 [-Werror=format-overflow=] sprintf(cs->info, "%d 0x%lx %s %s %s %s 0x%x 0x%x %d %d %s\n", ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/isdn/divert/isdn_divert.c:488:22: note: directive argument in the range [0, 255] drivers/isdn/divert/isdn_divert.c:488:4: note: 'sprintf' output 25 or more bytes (assuming 129) into a destination of size 90 This is unlikely to actually cause problems, so let's use snprintf as a simple workaround to shut up the warning and truncate the buffer instead. Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller --- drivers/isdn/divert/isdn_divert.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/isdn/divert/isdn_divert.c b/drivers/isdn/divert/isdn_divert.c index 060d357f107f..6f423bc49d0d 100644 --- a/drivers/isdn/divert/isdn_divert.c +++ b/drivers/isdn/divert/isdn_divert.c @@ -485,18 +485,19 @@ static int isdn_divert_icall(isdn_ctrl *ic) cs->deflect_dest[0] = '\0'; retval = 4; /* only proceed */ } - sprintf(cs->info, "%d 0x%lx %s %s %s %s 0x%x 0x%x %d %d %s\n", - cs->akt_state, - cs->divert_id, - divert_if.drv_to_name(cs->ics.driver), - (ic->command == ISDN_STAT_ICALLW) ? "1" : "0", - cs->ics.parm.setup.phone, - cs->ics.parm.setup.eazmsn, - cs->ics.parm.setup.si1, - cs->ics.parm.setup.si2, - cs->ics.parm.setup.screen, - dv->rule.waittime, - cs->deflect_dest); + snprintf(cs->info, sizeof(cs->info), + "%d 0x%lx %s %s %s %s 0x%x 0x%x %d %d %s\n", + cs->akt_state, + cs->divert_id, + divert_if.drv_to_name(cs->ics.driver), + (ic->command == ISDN_STAT_ICALLW) ? "1" : "0", + cs->ics.parm.setup.phone, + cs->ics.parm.setup.eazmsn, + cs->ics.parm.setup.si1, + cs->ics.parm.setup.si2, + cs->ics.parm.setup.screen, + dv->rule.waittime, + cs->deflect_dest); if ((dv->rule.action == DEFLECT_REPORT) || (dv->rule.action == DEFLECT_REJECT)) { put_info_buffer(cs->info);