CVE-2022-49390

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> macsec: fix UAF bug for real_dev<br /> <br /> Create a new macsec device but not get reference to real_dev. That can<br /> not ensure that real_dev is freed after macsec. That will trigger the<br /> UAF bug for real_dev as following:<br /> <br /> ==================================================================<br /> BUG: KASAN: use-after-free in macsec_get_iflink+0x5f/0x70 drivers/net/macsec.c:3662<br /> Call Trace:<br /> ...<br /> macsec_get_iflink+0x5f/0x70 drivers/net/macsec.c:3662<br /> dev_get_iflink+0x73/0xe0 net/core/dev.c:637<br /> default_operstate net/core/link_watch.c:42 [inline]<br /> rfc2863_policy+0x233/0x2d0 net/core/link_watch.c:54<br /> linkwatch_do_dev+0x2a/0x150 net/core/link_watch.c:161<br /> <br /> Allocated by task 22209:<br /> ...<br /> alloc_netdev_mqs+0x98/0x1100 net/core/dev.c:10549<br /> rtnl_create_link+0x9d7/0xc00 net/core/rtnetlink.c:3235<br /> veth_newlink+0x20e/0xa90 drivers/net/veth.c:1748<br /> <br /> Freed by task 8:<br /> ...<br /> kfree+0xd6/0x4d0 mm/slub.c:4552<br /> kvfree+0x42/0x50 mm/util.c:615<br /> device_release+0x9f/0x240 drivers/base/core.c:2229<br /> kobject_cleanup lib/kobject.c:673 [inline]<br /> kobject_release lib/kobject.c:704 [inline]<br /> kref_put include/linux/kref.h:65 [inline]<br /> kobject_put+0x1c8/0x540 lib/kobject.c:721<br /> netdev_run_todo+0x72e/0x10b0 net/core/dev.c:10327<br /> <br /> After commit faab39f63c1f ("net: allow out-of-order netdev unregistration")<br /> and commit e5f80fcf869a ("ipv6: give an IPv6 dev to blackhole_netdev"), we<br /> can add dev_hold_track() in macsec_dev_init() and dev_put_track() in<br /> macsec_free_netdev() to fix the problem.