net: bridge: remove redundant checks for null p->dev and p->br
A recent change added a null check on p->dev after p->dev was being
dereferenced by the ns_capable check on p->dev. It turns out that
neither the p->dev and p->br null checks are necessary, and can be
removed, which cleans up a static analyis warning.
As Nikolay Aleksandrov noted, these checks can be removed because:
"My reasoning of why it shouldn't be possible:
- On port add new_nbp() sets both p->dev and p->br before creating
kobj/sysfs
- On port del (trickier) del_nbp() calls kobject_del() before call_rcu()
to destroy the port which in turn calls sysfs_remove_dir() which uses
kernfs_remove() which deactivates (shouldn't be able to open new
files) and calls kernfs_drain() to drain current open/mmaped files in
the respective dir before continuing, thus making it impossible to
open a bridge port sysfs file with p->dev and p->br equal to NULL.
So I think it's safe to remove those checks altogether. It'd be nice to
get a second look over my reasoning as I might be missing something in
sysfs/kernfs call path."
Thanks to Nikolay Aleksandrov's suggestion to remove the check and
David Miller for sanity checking this.
Detected by CoverityScan, CID#751490 ("Dereference before null check")
Fixes: a5f3ea54f3cc ("net: bridge: add support for raw sysfs port options")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed
