From: Sergey Shtylyov Date: Fri, 6 Feb 2026 14:22:26 +0000 (+0300) Subject: media: dib8000: avoid division by 0 in dib8000_set_dds() X-Git-Tag: v7.1-rc1~169^2~165 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dde3c37af95cd6fa301c4906f33d627bc9dd874c;p=thirdparty%2Flinux.git media: dib8000: avoid division by 0 in dib8000_set_dds() In dib8000_set_dds(), 1 << 26 (67108864) divided by e.g. 1 apparently can't fit into 16-bit variable unit_khz_dds_val, being truncated to 0; this will cause division by 0 while calling dprintk() with debugging enabled (via the module parameter). Use s32 instead of s16 to declare the variable, getting rid of the cast to u16 in the *else* branch as well... Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool. Fixes: 173a64cb3fcf ("[media] dib8000: enhancement") Cc: stable@vger.kernel.org Signed-off-by: Sergey Shtylyov Signed-off-by: Hans Verkuil --- diff --git a/drivers/media/dvb-frontends/dib8000.c b/drivers/media/dvb-frontends/dib8000.c index ebef27bcc9899..d291113291e04 100644 --- a/drivers/media/dvb-frontends/dib8000.c +++ b/drivers/media/dvb-frontends/dib8000.c @@ -2695,7 +2695,7 @@ static void dib8000_viterbi_state(struct dib8000_state *state, u8 onoff) static void dib8000_set_dds(struct dib8000_state *state, s32 offset_khz) { - s16 unit_khz_dds_val; + s32 unit_khz_dds_val; u32 abs_offset_khz = abs(offset_khz); u32 dds = state->cfg.pll->ifreq & 0x1ffffff; u8 invert = !!(state->cfg.pll->ifreq & (1 << 25)); @@ -2716,7 +2716,7 @@ static void dib8000_set_dds(struct dib8000_state *state, s32 offset_khz) dds = (1<<26) - dds; } else { ratio = 2; - unit_khz_dds_val = (u16) (67108864 / state->cfg.pll->internal); + unit_khz_dds_val = 67108864 / state->cfg.pll->internal; if (offset_khz < 0) unit_khz_dds_val *= -1;