[Lunar, OEM-6.1, OEM-6.0, Kinetic, OEM-5.17, Jammy, Focal 0/1] CVE-2023-32233

[Thadeu Lima de Souza Cascardo]

[Impact]
On systems where user namespaces can be created by unprivileged users,
which is the default configuration on Ubuntu, unprivileged users can
trigger a use-after-free vulnerability on netfilter. This could be used to
crash the system or elevate privileges.

[Test case]
A PoC that crashes the system was tested and the fix has been shown to
prevent it.

[Backport]
The fix applies cleanly all the way back to 5.4 kernels. A backport to 4.15
is in the works.

[Potential impact]
netfilter users may find regressions when manipulating nftables.

Pablo Neira Ayuso (1):
  netfilter: nf_tables: deactivate anonymous set from preparation phase

 include/net/netfilter/nf_tables.h |  1 +
 net/netfilter/nf_tables_api.c     | 12 ++++++++++++
 net/netfilter/nft_dynset.c        |  2 +-
 net/netfilter/nft_lookup.c        |  2 +-
 net/netfilter/nft_objref.c        |  2 +-
 5 files changed, 16 insertions(+), 3 deletions(-)

-- 
2.34.1