Am 13.09.2016 um 11:15 hat Stefan Hajnoczi geschrieben: > Section "7.1.4 Use of library functions" in the C99 standard says: > > If an argument to a function has an invalid value (such as [...] > a null pointer [...]) [...] the behavior is undefined. > > Additionally the "searching and sorting" functions are specified as > requiring valid pointer values as described in 7.1.4. > > This patch fixes the following static analyzer errors:
"sanitizer", not "static analyzer" > block/qcow2.c:1807:41: runtime error: null pointer passed as argument 2, > which is declared to never be null > block/qcow2-cluster.c:86:26: runtime error: null pointer passed as argument > 2, which is declared to never be null > > Reported-by: Peter Maydell <[email protected]> > Signed-off-by: Stefan Hajnoczi <[email protected]> > --- > block/qcow2-cluster.c | 4 +++- > block/qcow2.c | 5 ++++- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c > index f941835..ab0dcdc 100644 > --- a/block/qcow2-cluster.c > +++ b/block/qcow2-cluster.c > @@ -83,7 +83,9 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t > min_size, > } > memset(new_l1_table, 0, align_offset(new_l1_size2, 512)); > > - memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t)); > + if (s->l1_table) { > + memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t)); > + } We could add 'else assert(s->l1_size == 0)' to make the intentions clearer. Or actually, maybe the simpler way would be to do 'if (s->l1_size)', then it's obvious that the skipped memcpy() wouldn't do anything anyway. > /* write new table (align to cluster) */ > BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE); > diff --git a/block/qcow2.c b/block/qcow2.c > index c079aa8..758a997 100644 > --- a/block/qcow2.c > +++ b/block/qcow2.c > @@ -1804,7 +1804,10 @@ static size_t header_ext_add(char *buf, uint32_t > magic, const void *s, > .magic = cpu_to_be32(magic), > .len = cpu_to_be32(len), > }; > - memcpy(buf + sizeof(QCowExtension), s, len); > + > + if (s) { > + memcpy(buf + sizeof(QCowExtension), s, len); > + } Same thing here. With or without the change: Reviewed-by: Kevin Wolf <[email protected]>
