[SRU][F/J][PATCH v2 0/1] CVE-2024-27397

[Massimiliano Pellizzer]

[Impact]

Add a timestamp field at the beginning of the transaction, store it
in the nftables per-netns area.

Update set backend .insert, .deactivate and sync gc path to use the
timestamp, this avoids that an element expires while control plane
transaction is still unfinished.

.lookup and .update, which are used from packet path, still use the
current time to check if the element has expired. And .get path and dump
also since this runs lockless under rcu read size lock. Then, there is
async gc which also needs to check the current time since it runs
asynchronously from a workqueue.

[Fix]

Noble:  Fixed
Jammy:  Cherry picked from linux-5.15.y
Focal:  Backported from linux-5.4.y
Bionic: Sent to ESM ML
Xenial: Sent to ESM ML

[Test Case]

Compile and boot tested.

[Where problems could occur]

The fix for CVE-2024-27397 affects the netfilter subsystem.
An issue with this fix may lead to kernel crashes, particularly during
the application or modification of network filtering rules.
Users may also notice unexpected network behavior.

[Changes between v1 and v2]
Fixed a typo in the commit description.

Pablo Neira Ayuso (1):
  netfilter: nf_tables: use timestamp to check for set element timeout

 include/net/netfilter/nf_tables.h | 21 +++++++++++++++++++--
 net/netfilter/nf_tables_api.c     |  1 +
 net/netfilter/nft_set_hash.c      |  8 +++++++-
 net/netfilter/nft_set_rbtree.c    |  6 ++++--
 4 files changed, 31 insertions(+), 5 deletions(-)

-- 
2.43.0