From df79d2bf95e0b490ad72f46d4b58581bd8f6fc7b Mon Sep 17 00:00:00 2001 From: Zhou Qingyang Date: Tue, 30 Nov 2021 16:38:05 +0100 Subject: [PATCH] media: dib8000: Fix a memleak in dib8000_init() [ Upstream commit 8dbdcc7269a83305ee9d677b75064d3530a48ee2 ] In dib8000_init(), the variable fe is not freed or passed out on the failure of dib8000_identify(&state->i2c), which could lead to a memleak. Fix this bug by adding a kfree of fe in the error path. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_DVB_DIB8000=m show no new warnings, and our static analyzer no longer warns about this code. Fixes: 77e2c0f5d471 ("V4L/DVB (12900): DiB8000: added support for DiBcom ISDB-T/ISDB-Tsb demodulator DiB8000") Signed-off-by: Zhou Qingyang Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/dvb-frontends/dib8000.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/media/dvb-frontends/dib8000.c b/drivers/media/dvb-frontends/dib8000.c index bb02354a48b8..d67f2dd997d0 100644 --- a/drivers/media/dvb-frontends/dib8000.c +++ b/drivers/media/dvb-frontends/dib8000.c @@ -4473,8 +4473,10 @@ static struct dvb_frontend *dib8000_init(struct i2c_adapter *i2c_adap, u8 i2c_ad state->timf_default = cfg->pll->timf; - if (dib8000_identify(&state->i2c) == 0) + if (dib8000_identify(&state->i2c) == 0) { + kfree(fe); goto error; + } dibx000_init_i2c_master(&state->i2c_master, DIB8000, state->i2c.adap, state->i2c.addr);