linux-stable.git/net/netfilter, branch v6.7.6

netfilter: ipset: Missing gc cancellations fixed

2024-02-23T08:51:58+00:00

commit 27c5a095e2518975e20a10102908ae8231699879 upstream.

The patch fdb8e12cc2cc ("netfilter: ipset: fix performance regression
in swap operation") missed to add the calls to gc cancellations
at the error path of create operations and at module unload. Also,
because the half of the destroy operations now executed by a
function registered by call_rcu(), neither NFNL_SUBSYS_IPSET mutex
or rcu read lock is held and therefore the checking of them results
false warnings.

Fixes: 97f7cf1cd80e ("netfilter: ipset: fix performance regression in swap operation")
Reported-by: syzbot+52bbc0ad036f6f0d4a25@syzkaller.appspotmail.com
Reported-by: Brad Spengler 
Reported-by: Стас Ничипорович 
Tested-by: Brad Spengler 
Tested-by: Стас Ничипорович 
Signed-off-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: ipset: fix performance regression in swap operation

2024-02-23T08:51:58+00:00

commit 97f7cf1cd80eeed3b7c808b7c12463295c751001 upstream.

The patch "netfilter: ipset: fix race condition between swap/destroy
and kernel side add/del/test", commit 28628fa9 fixes a race condition.
But the synchronize_rcu() added to the swap function unnecessarily slows
it down: it can safely be moved to destroy and use call_rcu() instead.

Eric Dumazet pointed out that simply calling the destroy functions as
rcu callback does not work: sets with timeout use garbage collectors
which need cancelling at destroy which can wait. Therefore the destroy
functions are split into two: cancelling garbage collectors safely at
executing the command received by netlink and moving the remaining
part only into the rcu callback.

Link: https://lore.kernel.org/lkml/C0829B10-EAA6-4809-874E-E1E9C05A8D84@automattic.com/
Fixes: 28628fa952fe ("netfilter: ipset: fix race condition between swap/destroy and kernel side add/del/test")
Reported-by: Ale Crismani 
Reported-by: David Wang <00107082@163.com>
Tested-by: David Wang <00107082@163.com>
Signed-off-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

work around gcc bugs with 'asm goto' with outputs

2024-02-23T08:51:20+00:00

commit 4356e9f841f7fbb945521cef3577ba394c65f3fc upstream.

We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f53 ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").

Then, much later, we ended up removing the workaround in commit
43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.

Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround.  But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.

It looks like there are at least two separate issues that all hit in
this area:

 (a) some versions of gcc don't mark the asm goto as 'volatile' when it
     has outputs:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420

     which is easy to work around by just adding the 'volatile' by hand.

 (b) Internal compiler errors:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422

     which are worked around by adding the extra empty 'asm' as a
     barrier, as in the original workaround.

but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.

but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.

Reported-and-tested-by: Sean Christopherson 
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers 
Cc: Uros Bizjak 
Cc: Jakub Jelinek 
Cc: Andrew Pinski 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

netfilter: nft_set_rbtree: skip end interval element from gc

2024-02-16T18:14:32+00:00

commit 60c0c230c6f046da536d3df8b39a20b9a9fd6af0 upstream.

rbtree lazy gc on insert might collect an end interval element that has
been just added in this transactions, skip end interval elements that
are not yet active.

Fixes: f718863aca46 ("netfilter: nft_set_rbtree: fix overlap expiration walk")
Cc: stable@vger.kernel.org
Reported-by: lonial con 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nft_set_pipapo: remove scratch_aligned pointer

2024-02-16T18:14:25+00:00

[ Upstream commit 5a8cdf6fd860ac5e6d08d72edbcecee049a7fec4 ]

use ->scratch for both avx2 and the generic implementation.

After previous change the scratch->map member is always aligned properly
for AVX2, so we can just use scratch->map in AVX2 too.

The alignoff delta is stored in the scratchpad so we can reconstruct
the correct address to free the area again.

Fixes: 7400b063969b ("nft_set_pipapo: Introduce AVX2-based lookup implementation")
Reviewed-by: Stefano Brivio 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nft_set_pipapo: add helper to release pcpu scratch area

2024-02-16T18:14:25+00:00

[ Upstream commit 47b1c03c3c1a119435480a1e73f27197dc59131d ]

After next patch simple kfree() is not enough anymore, so add
a helper for it.

Reviewed-by: Stefano Brivio 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Stable-dep-of: 5a8cdf6fd860 ("netfilter: nft_set_pipapo: remove scratch_aligned pointer")
Signed-off-by: Sasha Levin

netfilter: nft_set_pipapo: store index in scratch maps

2024-02-16T18:14:25+00:00

[ Upstream commit 76313d1a4aa9e30d5b43dee5efd8bcd4d8250006 ]

Pipapo needs a scratchpad area to keep state during matching.
This state can be large and thus cannot reside on stack.

Each set preallocates percpu areas for this.

On each match stage, one scratchpad half starts with all-zero and the other
is inited to all-ones.

At the end of each stage, the half that starts with all-ones is
always zero.  Before next field is tested, pointers to the two halves
are swapped, i.e.  resmap pointer turns into fill pointer and vice versa.

After the last field has been processed, pipapo stashes the
index toggle in a percpu variable, with assumption that next packet
will start with the all-zero half and sets all bits in the other to 1.

This isn't reliable.

There can be multiple sets and we can't be sure that the upper
and lower half of all set scratch map is always in sync (lookups
can be conditional), so one set might have swapped, but other might
not have been queried.

Thus we need to keep the index per-set-and-cpu, just like the
scratchpad.

Note that this bug fix is incomplete, there is a related issue.

avx2 and normal implementation might use slightly different areas of the
map array space due to the avx2 alignment requirements, so
m->scratch (generic/fallback implementation) and ->scratch_aligned
(avx) may partially overlap. scratch and scratch_aligned are not distinct
objects, the latter is just the aligned address of the former.

After this change, write to scratch_align->map_index may write to
scratch->map, so this issue becomes more prominent, we can set to 1
a bit in the supposedly-all-zero area of scratch->map[].

A followup patch will remove the scratch_aligned and makes generic and
avx code use the same (aligned) area.

Its done in a separate change to ease review.

Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Reviewed-by: Stefano Brivio 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nfnetlink_queue: un-break NF_REPEAT

2024-02-16T18:14:25+00:00

[ Upstream commit f82777e8ce6c039cdcacbcf1eb8619b99a20c06d ]

Only override userspace verdict if the ct hook returns something
other than ACCEPT.

Else, this replaces NF_REPEAT (run all hooks again) with NF_ACCEPT
(move to next hook).

Fixes: 6291b3a67ad5 ("netfilter: conntrack: convert nf_conntrack_update to netfilter verdicts")
Reported-by: l.6diay@passmail.com
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_tables: use timestamp to check for set element timeout

2024-02-16T18:14:25+00:00

[ Upstream commit 7395dfacfff65e9938ac0889dafa1ab01e987d15 ]

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.

Fixes: c3e1b005ed1c ("netfilter: nf_tables: add set element timeout support")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nft_ct: reject direction for ct id

2024-02-16T18:14:24+00:00

[ Upstream commit 38ed1c7062ada30d7c11e7a7acc749bf27aa14aa ]

Direction attribute is ignored, reject it in case this ever needs to be
supported

Fixes: 3087c3f7c23b ("netfilter: nft_ct: Add ct id support")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin