| Message ID | 20211130161224.181519-1-zhou1615@umn.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: meson: vdec: Fix a NULL pointer dereference in amvdec_add_ts() | expand |
On Wed, Dec 01, 2021 at 12:12:23AM +0800, Zhou Qingyang wrote: > diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c > index b9125c295d1d..41297c2f8f9a 100644 > --- a/drivers/staging/media/meson/vdec/vdec_helpers.c > +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c > @@ -234,6 +234,11 @@ void amvdec_add_ts(struct amvdec_session *sess, u64 ts, > unsigned long flags; > > new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL); > + if (!new_ts) { > + dev_err(sess->core->dev_dec, > + "No enough memory in %s\n", __func__); > + return; Please run checkpatch.pl on your patches. The dev_err() message should be deleted because kzalloc() already has a better message built in. WARNING: Possible unnecessary 'out of memory' message #50: FILE: drivers/staging/media/meson/vdec/vdec_helpers.c:238: + if (!new_ts) { + dev_err(sess->core->dev_dec, regards, dan carpenter
diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c index b9125c295d1d..41297c2f8f9a 100644 --- a/drivers/staging/media/meson/vdec/vdec_helpers.c +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c @@ -234,6 +234,11 @@ void amvdec_add_ts(struct amvdec_session *sess, u64 ts, unsigned long flags; new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL); + if (!new_ts) { + dev_err(sess->core->dev_dec, + "No enough memory in %s\n", __func__); + return; + } new_ts->ts = ts; new_ts->tc = tc; new_ts->offset = offset;
In amvdec_add_ts(), there is a dereference of kzalloc(), which could lead to a NULL pointer dereference on failure of kzalloc(). I fix this bug by adding a NULL check of new_ts. 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_VIDEO_MESON_VDEC=m show no new warnings, and our static analyzer no longer warns about this code. Fixes: 876f123b8956 ("media: meson: vdec: bring up to compliance") Signed-off-by: Zhou Qingyang <zhou1615@umn.edu> --- drivers/staging/media/meson/vdec/vdec_helpers.c | 5 +++++ 1 file changed, 5 insertions(+)