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| author | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2024-10-15 12:14:11 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2024-10-18 10:43:03 +0200 |
| commit | 576a307a7650bd544fbb24df801b9b7863b85e2f (patch) | |
| tree | 378ce31735d3d4d71e75bf2c8cc50b2bbe5f9d47 | |
| parent | 438d3085ba5b8b5bfa5290faa594e577f6ac9aa7 (diff) | |
| download | linux-576a307a7650bd544fbb24df801b9b7863b85e2f.tar.gz linux-576a307a7650bd544fbb24df801b9b7863b85e2f.tar.bz2 linux-576a307a7650bd544fbb24df801b9b7863b85e2f.zip | |
media: cx24116: prevent overflows on SNR calculus
as reported by Coverity, if reading SNR registers fail, a negative
number will be returned, causing an underflow when reading SNR
registers.
Prevent that.
Fixes: 8953db793d5b ("V4L/DVB (9178): cx24116: Add module parameter to return SNR as ESNO.")
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
| -rw-r--r-- | drivers/media/dvb-frontends/cx24116.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/media/dvb-frontends/cx24116.c b/drivers/media/dvb-frontends/cx24116.c index 8b978a9f74a4..f5dd3a81725a 100644 --- a/drivers/media/dvb-frontends/cx24116.c +++ b/drivers/media/dvb-frontends/cx24116.c @@ -741,6 +741,7 @@ static int cx24116_read_snr_pct(struct dvb_frontend *fe, u16 *snr) { struct cx24116_state *state = fe->demodulator_priv; u8 snr_reading; + int ret; static const u32 snr_tab[] = { /* 10 x Table (rounded up) */ 0x00000, 0x0199A, 0x03333, 0x04ccD, 0x06667, 0x08000, 0x0999A, 0x0b333, 0x0cccD, 0x0e667, @@ -749,7 +750,11 @@ static int cx24116_read_snr_pct(struct dvb_frontend *fe, u16 *snr) dprintk("%s()\n", __func__); - snr_reading = cx24116_readreg(state, CX24116_REG_QUALITY0); + ret = cx24116_readreg(state, CX24116_REG_QUALITY0); + if (ret < 0) + return ret; + + snr_reading = ret; if (snr_reading >= 0xa0 /* 100% */) *snr = 0xffff; |