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author | Jesper Juhl <jj@chaosbits.net> | 2011-02-17 17:33:56 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-03-22 06:51:55 -0300 |
commit | 7e270941c8f0a11224e383d3d38946451f66fbbf (patch) | |
tree | 8cd6d401c30d854c355c13bbd992a712a30e34d0 /drivers/media/dvb/frontends | |
parent | 35d9f510b67b10338161aba6229d4f55b4000f5b (diff) | |
download | op-kernel-dev-7e270941c8f0a11224e383d3d38946451f66fbbf.zip op-kernel-dev-7e270941c8f0a11224e383d3d38946451f66fbbf.tar.gz |
[media] Zarlink zl10036 DVB-S: Fix mem leak in zl10036_attach
On Thu, 17 Feb 2011, Matthias Schwarzott wrote:
> On Sunday 06 February 2011, Jesper Juhl wrote:
> > If the memory allocation to 'state' succeeds but we jump to the 'error'
> > label before 'state' is assigned to fe->tuner_priv, then the call to
> > 'zl10036_release(fe)' at the 'error:' label will not free 'state', but
> > only what was previously assigned to 'tuner_priv', thus leaking the memory
> > allocated to 'state'.
> > There are may ways to fix this, including assigning the allocated memory
> > directly to 'fe->tuner_priv', but I did not go for that since the
> > additional pointer derefs are more expensive than the local variable, so I
> > just added a 'kfree(state)' call. I guess the call to 'zl10036_release'
> > might not even be needed in this case, but I wasn't sure, so I left it in.
> >
> Yeah, that call to zl10036_release can be completely eleminated.
> Another thing is: jumping to the error label only makes sense when memory was
> already allocated. So the jump in line 471 can be replaced by "return NULL",
> as the other error handling before allocation:
> if (NULL == config) {
> printk(KERN_ERR "%s: no config specified", __func__);
> goto error;
> }
>
> I suggest to improve the patch to clean the code up when changing that.
>
> But I am fine with commiting this patch also if you do not want to change it.
>
Thank you for your feedback. It makes a lot of sense.
Changing it is not a problem :)
How about the updated patch below?
If the memory allocation to 'state' succeeds but we jump to the 'error'
label before 'state' is assigned to fe->tuner_priv, then the call to
'zl10036_release(fe)' at the 'error:' label will not free 'state', but
only what was previously assigned to 'tuner_priv', thus leaking the memory
allocated to 'state'.
This patch fixes the leak and also does not jump to 'error:' before mem
has been allocated but instead just returns. Also some small style
cleanups.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/dvb/frontends')
-rw-r--r-- | drivers/media/dvb/frontends/zl10036.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/media/dvb/frontends/zl10036.c b/drivers/media/dvb/frontends/zl10036.c index 4627f49..81aa984 100644 --- a/drivers/media/dvb/frontends/zl10036.c +++ b/drivers/media/dvb/frontends/zl10036.c @@ -463,16 +463,16 @@ struct dvb_frontend *zl10036_attach(struct dvb_frontend *fe, const struct zl10036_config *config, struct i2c_adapter *i2c) { - struct zl10036_state *state = NULL; + struct zl10036_state *state; int ret; - if (NULL == config) { + if (!config) { printk(KERN_ERR "%s: no config specified", __func__); - goto error; + return NULL; } state = kzalloc(sizeof(struct zl10036_state), GFP_KERNEL); - if (NULL == state) + if (!state) return NULL; state->config = config; @@ -507,7 +507,7 @@ struct dvb_frontend *zl10036_attach(struct dvb_frontend *fe, return fe; error: - zl10036_release(fe); + kfree(state); return NULL; } EXPORT_SYMBOL(zl10036_attach); |