Messages in this thread | | | Subject | Re: [PATCH] media: videobuf2-core: Fix error handling when fileio is deallocated | From | Hans Verkuil <> | Date | Tue, 13 Nov 2018 12:56:18 +0100 |
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On 11/13/18 11:27, Marek Szyprowski wrote: > Hi Myungho, > > On 2018-11-12 01:49, Myungho Jung wrote: >> The mutex that is held from vb2_fop_read() can be unlocked while waiting >> for a buffer if the queue is streaming and blocking. Meanwhile, fileio >> can be released. So, it should return an error if the fileio address is >> changed. >> >> Signed-off-by: Myungho Jung <mhjungk@gmail.com> >> Reported-by: syzbot+4180ff9ca6810b06c1e9@syzkaller.appspotmail.com > > Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Sorry:
Nacked-by: Hans Verkuil <hans.verkuil@cisco.com>
This addresses the symptom, not the underlying cause.
I have a patch that fixes the actual cause that I plan to post soon after I review it a bit more.
Regards,
Hans
> > Thanks for analyzing the code and fixing this issue! > >> --- >> drivers/media/common/videobuf2/videobuf2-core.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c >> index 975ff5669f72..bff94752eb27 100644 >> --- a/drivers/media/common/videobuf2/videobuf2-core.c >> +++ b/drivers/media/common/videobuf2/videobuf2-core.c >> @@ -2564,6 +2564,10 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_ >> dprintk(5, "vb2_dqbuf result: %d\n", ret); >> if (ret) >> return ret; >> + if (fileio != q->fileio) { >> + dprintk(3, "fileio deallocated\n"); >> + return -EFAULT; >> + } >> fileio->dq_count += 1; >> >> fileio->cur_index = index; > > Best regards >
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