On Mon 04-11-24 00:42:39, Daniel Yang wrote: > The function iter_file_splice_write() calls pipe_buf_release() which has > a nullptr dereference in ops->release. Add check for buf->ops not null > before calling pipe_buf_release(). > > Signed-off-by: Daniel Yang <danielyangkang@xxxxxxxxx> > Reported-by: syzbot+d2125fcb6aa8c4276fd2@xxxxxxxxxxxxxxxxxxxxxxxxx > Closes: https://syzkaller.appspot.com/bug?extid=d2125fcb6aa8c4276fd2 > Fixes: 2df86547b23d ("netfs: Cut over to using new writeback code") > --- > fs/splice.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/splice.c b/fs/splice.c > index 06232d7e5..b8c503e47 100644 > --- a/fs/splice.c > +++ b/fs/splice.c > @@ -756,7 +756,8 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, > if (ret >= buf->len) { > ret -= buf->len; > buf->len = 0; > - pipe_buf_release(pipe, buf); > + if (buf->ops) > + pipe_buf_release(pipe, buf); Umm, already released pipe buf? How would it get here? We have filled the buffers shortly before so IMHO it indicates some deeper problem. Can you please explain a bit more? Honza > tail++; > pipe->tail = tail; > if (pipe->files) > -- > 2.39.2 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
