| Message ID | 20211215033535.40422-1-zhou1615@umn.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] media: meson: vdec: Fix a NULL pointer dereference in amvdec_add_ts() | expand |
Zhou Qingyang, this is exactly the patch Neil wrote, except you just stuck your name on it. Not nice. Neil, can you post your patch with your own Signed-off-by, then I'll take that one. Regards, Hans On 15/12/2021 04:35, Zhou Qingyang wrote: > In amvdec_add_ts(), there is a dereference of kzalloc(), which could lead > to a NULL pointer dereference on failure of kzalloc(). > > Fix this bug by adding a NULL check of new_ts. > > This bug was found by a static analyzer[1]. > > 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> > --- > > [1] 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. > > Changes in v3: > - Change the description of patch > - Turn the return type from 'void' to 'int' > - Check the return value in the caller 'esparser_queue()' > > Changes in v2: > - Delete dev_err() message > > drivers/staging/media/meson/vdec/esparser.c | 7 ++++++- > drivers/staging/media/meson/vdec/vdec_helpers.c | 8 ++++++-- > drivers/staging/media/meson/vdec/vdec_helpers.h | 4 ++-- > 3 files changed, 14 insertions(+), 5 deletions(-) > > diff --git a/drivers/staging/media/meson/vdec/esparser.c b/drivers/staging/media/meson/vdec/esparser.c > index db7022707ff8..095100a50da8 100644 > --- a/drivers/staging/media/meson/vdec/esparser.c > +++ b/drivers/staging/media/meson/vdec/esparser.c > @@ -328,7 +328,12 @@ esparser_queue(struct amvdec_session *sess, struct vb2_v4l2_buffer *vbuf) > > offset = esparser_get_offset(sess); > > - amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); > + ret = amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); > + if (!ret) { > + v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR); > + return ret; > + } > + > dev_dbg(core->dev, "esparser: ts = %llu pld_size = %u offset = %08X flags = %08X\n", > vb->timestamp, payload_size, offset, vbuf->flags); > > diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c > index b9125c295d1d..06fd66539797 100644 > --- a/drivers/staging/media/meson/vdec/vdec_helpers.c > +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c > @@ -227,13 +227,16 @@ int amvdec_set_canvases(struct amvdec_session *sess, > } > EXPORT_SYMBOL_GPL(amvdec_set_canvases); > > -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, > - struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) > +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, > + struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) > { > struct amvdec_timestamp *new_ts; > unsigned long flags; > > new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL); > + if (!new_ts) > + return -ENOMEM; > + > new_ts->ts = ts; > new_ts->tc = tc; > new_ts->offset = offset; > @@ -242,6 +245,7 @@ void amvdec_add_ts(struct amvdec_session *sess, u64 ts, > spin_lock_irqsave(&sess->ts_spinlock, flags); > list_add_tail(&new_ts->list, &sess->timestamps); > spin_unlock_irqrestore(&sess->ts_spinlock, flags); > + return 0; > } > EXPORT_SYMBOL_GPL(amvdec_add_ts); > > diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.h b/drivers/staging/media/meson/vdec/vdec_helpers.h > index 88137d15aa3a..4bf3e61d081b 100644 > --- a/drivers/staging/media/meson/vdec/vdec_helpers.h > +++ b/drivers/staging/media/meson/vdec/vdec_helpers.h > @@ -56,8 +56,8 @@ void amvdec_dst_buf_done_offset(struct amvdec_session *sess, > * @offset: offset in the VIFIFO where the associated packet was written > * @flags: the vb2_v4l2_buffer flags > */ > -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, > - struct v4l2_timecode tc, u32 offset, u32 flags); > +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, > + struct v4l2_timecode tc, u32 offset, u32 flags); > void amvdec_remove_ts(struct amvdec_session *sess, u64 ts); > > /**
Hi, On 11/01/2022 14:03, Qingyang Zhou wrote: > Hi Hans: > > Here I certify that this is an origin patch I wrote. I did not copy Neil's patch, and I did not know his patch. > > Neil, please post your original patch here, so everyone can see both patches. > > Yours > Zhou Qingyang. > > On Tue, Jan 11, 2022 at 5:16 PM Hans Verkuil <hverkuil-cisco@xs4all.nl <mailto:hverkuil-cisco@xs4all.nl>> wrote: > > Zhou Qingyang, this is exactly the patch Neil wrote, except you just stuck your > name on it. Not nice. > > Neil, can you post your patch with your own Signed-off-by, then I'll take that one. > > Regards, > > Hans > > On 15/12/2021 04:35, Zhou Qingyang wrote: > > In amvdec_add_ts(), there is a dereference of kzalloc(), which could lead > > to a NULL pointer dereference on failure of kzalloc(). > > > > Fix this bug by adding a NULL check of new_ts. > > > > This bug was found by a static analyzer[1]. > > > > 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 <mailto:zhou1615@umn.edu>> > > --- > > > > [1] 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. > > > > Changes in v3: > > - Change the description of patch > > - Turn the return type from 'void' to 'int' > > - Check the return value in the caller 'esparser_queue()' > > > > Changes in v2: > > - Delete dev_err() message > > > > drivers/staging/media/meson/vdec/esparser.c | 7 ++++++- > > drivers/staging/media/meson/vdec/vdec_helpers.c | 8 ++++++-- > > drivers/staging/media/meson/vdec/vdec_helpers.h | 4 ++-- > > 3 files changed, 14 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/staging/media/meson/vdec/esparser.c b/drivers/staging/media/meson/vdec/esparser.c > > index db7022707ff8..095100a50da8 100644 > > --- a/drivers/staging/media/meson/vdec/esparser.c > > +++ b/drivers/staging/media/meson/vdec/esparser.c > > @@ -328,7 +328,12 @@ esparser_queue(struct amvdec_session *sess, struct vb2_v4l2_buffer *vbuf) > > > > offset = esparser_get_offset(sess); > > > > - amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); > > + ret = amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); > > + if (!ret) { > > + v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR); > > + return ret; > > + } > > + > > dev_dbg(core->dev, "esparser: ts = %llu pld_size = %u offset = %08X flags = %08X\n", > > vb->timestamp, payload_size, offset, vbuf->flags); > > > > diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c > > index b9125c295d1d..06fd66539797 100644 > > --- a/drivers/staging/media/meson/vdec/vdec_helpers.c > > +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c > > @@ -227,13 +227,16 @@ int amvdec_set_canvases(struct amvdec_session *sess, > > } > > EXPORT_SYMBOL_GPL(amvdec_set_canvases); > > > > -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, > > - struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) > > +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, > > + struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) > > { > > struct amvdec_timestamp *new_ts; > > unsigned long flags; > > > > new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL); > > + if (!new_ts) > > + return -ENOMEM; > > + > > new_ts->ts = ts; > > new_ts->tc = tc; > > new_ts->offset = offset; > > @@ -242,6 +245,7 @@ void amvdec_add_ts(struct amvdec_session *sess, u64 ts, > > spin_lock_irqsave(&sess->ts_spinlock, flags); > > list_add_tail(&new_ts->list, &sess->timestamps); > > spin_unlock_irqrestore(&sess->ts_spinlock, flags); > > + return 0; > > } > > EXPORT_SYMBOL_GPL(amvdec_add_ts); > > > > diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.h b/drivers/staging/media/meson/vdec/vdec_helpers.h > > index 88137d15aa3a..4bf3e61d081b 100644 > > --- a/drivers/staging/media/meson/vdec/vdec_helpers.h > > +++ b/drivers/staging/media/meson/vdec/vdec_helpers.h > > @@ -56,8 +56,8 @@ void amvdec_dst_buf_done_offset(struct amvdec_session *sess, > > * @offset: offset in the VIFIFO where the associated packet was written > > * @flags: the vb2_v4l2_buffer flags > > */ > > -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, > > - struct v4l2_timecode tc, u32 offset, u32 flags); > > +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, > > + struct v4l2_timecode tc, u32 offset, u32 flags); > > void amvdec_remove_ts(struct amvdec_session *sess, u64 ts); > > > > /** > Let's inspect: I posted a probable solution the 09/12/2021 in a reply to 20211209085840.2081024-1-jiasheng@iscas.ac.cn : ===================><============================= diff --git a/drivers/staging/media/meson/vdec/esparser.c b/drivers/staging/media/meson/vdec/esparser.c index db7022707ff8..df733eff9ac7 100644 --- a/drivers/staging/media/meson/vdec/esparser.c +++ b/drivers/staging/media/meson/vdec/esparser.c @@ -328,7 +328,11 @@ esparser_queue(struct amvdec_session *sess, struct vb2_v4l2_buffer *vbuf) offset = esparser_get_offset(sess); - amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); + ret = amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); + if (ret) { + v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR); + return ret; + } dev_dbg(core->dev, "esparser: ts = %llu pld_size = %u offset = %08X flags = %08X\n", vb->timestamp, payload_size, offset, vbuf->flags); diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c index b9125c295d1d..593b2ccbece2 100644 --- a/drivers/staging/media/meson/vdec/vdec_helpers.c +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c @@ -227,13 +227,15 @@ int amvdec_set_canvases(struct amvdec_session *sess, } EXPORT_SYMBOL_GPL(amvdec_set_canvases); -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, - struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, + struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) { struct amvdec_timestamp *new_ts; unsigned long flags; new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL); + if (!new_ts) + return -ENOMEM; new_ts->ts = ts; new_ts->tc = tc; new_ts->offset = offset; diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.h b/drivers/staging/media/meson/vdec/vdec_helpers.h index 88137d15aa3a..4bf3e61d081b 100644 --- a/drivers/staging/media/meson/vdec/vdec_helpers.h +++ b/drivers/staging/media/meson/vdec/vdec_helpers.h @@ -56,8 +56,8 @@ void amvdec_dst_buf_done_offset(struct amvdec_session *sess, * @offset: offset in the VIFIFO where the associated packet was written * @flags: the vb2_v4l2_buffer flags */ -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, - struct v4l2_timecode tc, u32 offset, u32 flags); +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, + struct v4l2_timecode tc, u32 offset, u32 flags); void amvdec_remove_ts(struct amvdec_session *sess, u64 ts); ===================><============================= Then the patches were sent: - 20211210015620.2143555-1-jiasheng@iscas.ac.cn on 10/12/2021 - 20211215033535.40422-1-zhou1615@umn.edu on 15/12/2021 They are extremely close but not similar, mostly indenting differs. Both patches have the missing final "return 0" in amvdec_add_ts which is missing in my proposal. But only 20211210015620.2143555-1-jiasheng@iscas.ac.cn has the correct "if (ret)" in esparser_queue(). Patch 20211215033535.40422-1-zhou1615@umn.ed has a wrong "if (!ret)". But when comparing, 20211215033535.40422-1-zhou1615@umn.edu is an almost exact copy of my proposal, minus the fixes and the bogus return check. To be honest, there is a limited way to fix this, it's probable 20211215033535.40422-1-zhou1615@umn.edu was written independently from my proposal since there is a bug return check, and 20211210015620.2143555-1-jiasheng@iscas.ac.cn was rewritten from my proposal. Since 20211215033535.40422-1-zhou1615@umn.ed has a bogus return check, it should be naked. I'll only ask 20211210015620.2143555-1-jiasheng@iscas.ac.cn to be resent with a "Suggested-by" and indentation fixed like my proposal. Neil
diff --git a/drivers/staging/media/meson/vdec/esparser.c b/drivers/staging/media/meson/vdec/esparser.c index db7022707ff8..095100a50da8 100644 --- a/drivers/staging/media/meson/vdec/esparser.c +++ b/drivers/staging/media/meson/vdec/esparser.c @@ -328,7 +328,12 @@ esparser_queue(struct amvdec_session *sess, struct vb2_v4l2_buffer *vbuf) offset = esparser_get_offset(sess); - amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); + ret = amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags); + if (!ret) { + v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR); + return ret; + } + dev_dbg(core->dev, "esparser: ts = %llu pld_size = %u offset = %08X flags = %08X\n", vb->timestamp, payload_size, offset, vbuf->flags); diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c index b9125c295d1d..06fd66539797 100644 --- a/drivers/staging/media/meson/vdec/vdec_helpers.c +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c @@ -227,13 +227,16 @@ int amvdec_set_canvases(struct amvdec_session *sess, } EXPORT_SYMBOL_GPL(amvdec_set_canvases); -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, - struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, + struct v4l2_timecode tc, u32 offset, u32 vbuf_flags) { struct amvdec_timestamp *new_ts; unsigned long flags; new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL); + if (!new_ts) + return -ENOMEM; + new_ts->ts = ts; new_ts->tc = tc; new_ts->offset = offset; @@ -242,6 +245,7 @@ void amvdec_add_ts(struct amvdec_session *sess, u64 ts, spin_lock_irqsave(&sess->ts_spinlock, flags); list_add_tail(&new_ts->list, &sess->timestamps); spin_unlock_irqrestore(&sess->ts_spinlock, flags); + return 0; } EXPORT_SYMBOL_GPL(amvdec_add_ts); diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.h b/drivers/staging/media/meson/vdec/vdec_helpers.h index 88137d15aa3a..4bf3e61d081b 100644 --- a/drivers/staging/media/meson/vdec/vdec_helpers.h +++ b/drivers/staging/media/meson/vdec/vdec_helpers.h @@ -56,8 +56,8 @@ void amvdec_dst_buf_done_offset(struct amvdec_session *sess, * @offset: offset in the VIFIFO where the associated packet was written * @flags: the vb2_v4l2_buffer flags */ -void amvdec_add_ts(struct amvdec_session *sess, u64 ts, - struct v4l2_timecode tc, u32 offset, u32 flags); +int amvdec_add_ts(struct amvdec_session *sess, u64 ts, + struct v4l2_timecode tc, u32 offset, u32 flags); void amvdec_remove_ts(struct amvdec_session *sess, u64 ts); /**
In amvdec_add_ts(), there is a dereference of kzalloc(), which could lead to a NULL pointer dereference on failure of kzalloc(). Fix this bug by adding a NULL check of new_ts. This bug was found by a static analyzer[1]. 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> --- [1] 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. Changes in v3: - Change the description of patch - Turn the return type from 'void' to 'int' - Check the return value in the caller 'esparser_queue()' Changes in v2: - Delete dev_err() message drivers/staging/media/meson/vdec/esparser.c | 7 ++++++- drivers/staging/media/meson/vdec/vdec_helpers.c | 8 ++++++-- drivers/staging/media/meson/vdec/vdec_helpers.h | 4 ++-- 3 files changed, 14 insertions(+), 5 deletions(-)