| Message ID | 1539981546-10596-4-git-send-email-Liam.Merwick@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | off-by-one and NULL pointer accesses detected by static analysis | expand |
On 19.10.18 22:39, Liam Merwick wrote: > The dev_id returned by the call to blk_get_attached_dev_id() in > blk_root_get_parent_desc() can be NULL (an internal call to > object_get_canonical_path may have returned NULL). > > Instead of just checking this case before before dereferencing, > adjust blk_get_attached_dev_id() to return the empty string if no > object path can be found (similar to the case when blk->dev is NULL > and an empty string is returned). > > Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com> > --- > block/block-backend.c | 6 +++++- > dtc | 2 +- > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/block/block-backend.c b/block/block-backend.c > index dc0cd5772413..e628920f3cd8 100644 > --- a/block/block-backend.c > +++ b/block/block-backend.c > @@ -909,6 +909,7 @@ void *blk_get_attached_dev(BlockBackend *blk) > char *blk_get_attached_dev_id(BlockBackend *blk) > { > DeviceState *dev; > + char *dev_id; > > assert(!blk->legacy_dev); > dev = blk->dev; > @@ -918,7 +919,10 @@ char *blk_get_attached_dev_id(BlockBackend *blk) > } else if (dev->id) { > return g_strdup(dev->id); > } > - return object_get_canonical_path(OBJECT(dev)); > + > + dev_id = object_get_canonical_path(OBJECT(dev)); > + > + return dev_id ? dev_id : g_strdup(""); > } > > /* Looks good, but since you'll have to respin anyway because of the hunk below, you may want to consider return object_get_canonical_path(OBJECT(dev)) ?: g_strdup(""); instead. (We have several instances of binary "?:" in the code already, so it's fine to use it. Of course you don't have to, though, if you don't like it.) > diff --git a/dtc b/dtc > index 88f18909db73..e54388015af1 160000 > --- a/dtc > +++ b/dtc > @@ -1 +1 @@ > -Subproject commit 88f18909db731a627456f26d779445f84e449536 > +Subproject commit e54388015af1fb4bf04d0bca99caba1074d9cc42 I don't think this hunk belongs here. Max
On 04/11/18 23:57, Max Reitz wrote: > On 19.10.18 22:39, Liam Merwick wrote: >> The dev_id returned by the call to blk_get_attached_dev_id() in >> blk_root_get_parent_desc() can be NULL (an internal call to >> object_get_canonical_path may have returned NULL). >> >> Instead of just checking this case before before dereferencing, >> adjust blk_get_attached_dev_id() to return the empty string if no >> object path can be found (similar to the case when blk->dev is NULL >> and an empty string is returned). >> >> Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com> >> --- >> block/block-backend.c | 6 +++++- >> dtc | 2 +- >> 2 files changed, 6 insertions(+), 2 deletions(-) >> >> diff --git a/block/block-backend.c b/block/block-backend.c >> index dc0cd5772413..e628920f3cd8 100644 >> --- a/block/block-backend.c >> +++ b/block/block-backend.c >> @@ -909,6 +909,7 @@ void *blk_get_attached_dev(BlockBackend *blk) >> char *blk_get_attached_dev_id(BlockBackend *blk) >> { >> DeviceState *dev; >> + char *dev_id; >> >> assert(!blk->legacy_dev); >> dev = blk->dev; >> @@ -918,7 +919,10 @@ char *blk_get_attached_dev_id(BlockBackend *blk) >> } else if (dev->id) { >> return g_strdup(dev->id); >> } >> - return object_get_canonical_path(OBJECT(dev)); >> + >> + dev_id = object_get_canonical_path(OBJECT(dev)); >> + >> + return dev_id ? dev_id : g_strdup(""); >> } >> >> /* > > Looks good, but since you'll have to respin anyway because of the hunk > below, you may want to consider > > return object_get_canonical_path(OBJECT(dev)) ?: g_strdup(""); > > instead. (We have several instances of binary "?:" in the code already, > so it's fine to use it. Of course you don't have to, though, if you > don't like it.) > I like it. Will make that change in v5 >> diff --git a/dtc b/dtc >> index 88f18909db73..e54388015af1 160000 >> --- a/dtc >> +++ b/dtc >> @@ -1 +1 @@ >> -Subproject commit 88f18909db731a627456f26d779445f84e449536 >> +Subproject commit e54388015af1fb4bf04d0bca99caba1074d9cc42 > > I don't think this hunk belongs here. Indeed. Regards, Liam
diff --git a/block/block-backend.c b/block/block-backend.c index dc0cd5772413..e628920f3cd8 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -909,6 +909,7 @@ void *blk_get_attached_dev(BlockBackend *blk) char *blk_get_attached_dev_id(BlockBackend *blk) { DeviceState *dev; + char *dev_id; assert(!blk->legacy_dev); dev = blk->dev; @@ -918,7 +919,10 @@ char *blk_get_attached_dev_id(BlockBackend *blk) } else if (dev->id) { return g_strdup(dev->id); } - return object_get_canonical_path(OBJECT(dev)); + + dev_id = object_get_canonical_path(OBJECT(dev)); + + return dev_id ? dev_id : g_strdup(""); } /* diff --git a/dtc b/dtc index 88f18909db73..e54388015af1 160000 --- a/dtc +++ b/dtc @@ -1 +1 @@ -Subproject commit 88f18909db731a627456f26d779445f84e449536 +Subproject commit e54388015af1fb4bf04d0bca99caba1074d9cc42
The dev_id returned by the call to blk_get_attached_dev_id() in blk_root_get_parent_desc() can be NULL (an internal call to object_get_canonical_path may have returned NULL). Instead of just checking this case before before dereferencing, adjust blk_get_attached_dev_id() to return the empty string if no object path can be found (similar to the case when blk->dev is NULL and an empty string is returned). Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com> --- block/block-backend.c | 6 +++++- dtc | 2 +- 2 files changed, 6 insertions(+), 2 deletions(-)