From a132fef816606ebe9d20895b1535582bfede12a4 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 28 Oct 2014 11:07:03 -0200 Subject: [PATCH] [media] lgdt3306a: don't go past the buffer As warned by smatch: drivers/media/dvb-frontends/lgdt3306a.c:1354 log10_x1000() error: buffer overflow 'valx_x10' 14 <= 14 drivers/media/dvb-frontends/lgdt3306a.c:1355 log10_x1000() error: buffer overflow 'log10x_x1000' 14 <= 14 There's a potential of returning a value out of the buffer. Fix it. While here, remove the ugly braced block. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/lgdt3306a.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/media/dvb-frontends/lgdt3306a.c b/drivers/media/dvb-frontends/lgdt3306a.c index c8af071ce40b..92affe124a8d 100644 --- a/drivers/media/dvb-frontends/lgdt3306a.c +++ b/drivers/media/dvb-frontends/lgdt3306a.c @@ -1319,6 +1319,7 @@ static u32 log10_x1000(u32 x) static u32 valx_x10[] = { 10, 11, 13, 15, 17, 20, 25, 33, 41, 50, 59, 73, 87, 100 }; static u32 log10x_x1000[] = { 0, 41, 114, 176, 230, 301, 398, 518, 613, 699, 771, 863, 939, 1000 }; static u32 nelems = sizeof(valx_x10)/sizeof(valx_x10[0]); + u32 diff_val, step_val, step_log10; u32 log_val = 0; u32 i; @@ -1348,15 +1349,16 @@ static u32 log10_x1000(u32 x) if (valx_x10[i] >= x) break; } + if (i == nelems) + return log_val + log10x_x1000[i - 1]; - { - u32 diff_val = x - valx_x10[i-1]; - u32 step_val = valx_x10[i] - valx_x10[i-1]; - u32 step_log10 = log10x_x1000[i] - log10x_x1000[i-1]; - /* do a linear interpolation to get in-between values */ - return log_val + log10x_x1000[i-1] + - ((diff_val*step_log10) / step_val); - } + diff_val = x - valx_x10[i-1]; + step_val = valx_x10[i] - valx_x10[i - 1]; + step_log10 = log10x_x1000[i] - log10x_x1000[i - 1]; + + /* do a linear interpolation to get in-between values */ + return log_val + log10x_x1000[i - 1] + + ((diff_val*step_log10) / step_val); } static u32 lgdt3306a_calculate_snr_x100(struct lgdt3306a_state *state) -- 2.34.1