This is a note to let you know that I've just added the patch titled
netfilter: nf_tables: fix memleak when more than 255 elements expired
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-nf_tables-fix-memleak-when-more-than-255-elements-expired.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable-owner@xxxxxxxxxxxxxxx Tue Nov 21 12:13:57 2023
From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date: Tue, 21 Nov 2023 13:13:27 +0100
Subject: netfilter: nf_tables: fix memleak when more than 255 elements expired
To: netfilter-devel@xxxxxxxxxxxxxxx
Cc: gregkh@xxxxxxxxxxxxxxxxxxx, sashal@xxxxxxxxxx, stable@xxxxxxxxxxxxxxx
Message-ID: <20231121121333.294238-21-pablo@xxxxxxxxxxxxx>
From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
commit cf5000a7787cbc10341091d37245a42c119d26c5 upstream.
When more than 255 elements expired we're supposed to switch to a new gc
container structure.
This never happens: u8 type will wrap before reaching the boundary
and nft_trans_gc_space() always returns true.
This means we recycle the initial gc container structure and
lose track of the elements that came before.
While at it, don't deref 'gc' after we've passed it to call_rcu.
Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Reported-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/netfilter/nf_tables.h | 2 +-
net/netfilter/nf_tables_api.c | 10 ++++++++--
2 files changed, 9 insertions(+), 3 deletions(-)
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1440,7 +1440,7 @@ struct nft_trans_gc {
struct net *net;
struct nft_set *set;
u32 seq;
- u8 count;
+ u16 count;
void *priv[NFT_TRANS_GC_BATCHCOUNT];
struct rcu_head rcu;
};
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7089,12 +7089,15 @@ static int nft_trans_gc_space(struct nft
struct nft_trans_gc *nft_trans_gc_queue_async(struct nft_trans_gc *gc,
unsigned int gc_seq, gfp_t gfp)
{
+ struct nft_set *set;
+
if (nft_trans_gc_space(gc))
return gc;
+ set = gc->set;
nft_trans_gc_queue_work(gc);
- return nft_trans_gc_alloc(gc->set, gc_seq, gfp);
+ return nft_trans_gc_alloc(set, gc_seq, gfp);
}
EXPORT_SYMBOL_GPL(nft_trans_gc_queue_async);
@@ -7111,15 +7114,18 @@ EXPORT_SYMBOL_GPL(nft_trans_gc_queue_asy
struct nft_trans_gc *nft_trans_gc_queue_sync(struct nft_trans_gc *gc, gfp_t gfp)
{
+ struct nft_set *set;
+
if (WARN_ON_ONCE(!lockdep_commit_lock_is_held(gc->net)))
return NULL;
if (nft_trans_gc_space(gc))
return gc;
+ set = gc->set;
call_rcu(&gc->rcu, nft_trans_gc_trans_free);
- return nft_trans_gc_alloc(gc->set, 0, gfp);
+ return nft_trans_gc_alloc(set, 0, gfp);
}
EXPORT_SYMBOL_GPL(nft_trans_gc_queue_sync);
Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are
queue-5.4/netfilter-nf_tables-fix-memleak-when-more-than-255-elements-expired.patch
queue-5.4/netfilter-nft_set_rbtree-fix-overlap-expiration-walk.patch
queue-5.4/netfilter-nf_tables-use-correct-lock-to-protect-gc_list.patch
queue-5.4/netfilter-nf_tables-disable-toggling-dormant-table-state-more-than-once.patch
queue-5.4/netfilter-nf_tables-gc-transaction-race-with-netns-dismantle.patch
queue-5.4/netfilter-nf_tables-drop-map-element-references-from-preparation-phase.patch
queue-5.4/netfilter-nf_tables-fix-gc-transaction-races-with-netns-and-netlink-event-exit-path.patch
queue-5.4/netfilter-nf_tables-don-t-skip-expired-elements-during-walk.patch
queue-5.4/netfilter-nf_tables-remove-busy-mark-and-gc-batch-api.patch
queue-5.4/netfilter-nf_tables-gc-transaction-race-with-abort-path.patch
queue-5.4/netfilter-nf_tables-unregister-flowtable-hooks-on-netns-exit.patch
queue-5.4/netfilter-nft_set_rbtree-switch-to-node-list-walk-for-overlap-detection.patch
queue-5.4/netfilter-nf_tables-adapt-set-backend-to-use-gc-transaction-api.patch
queue-5.4/netfilter-nftables-rename-set-element-data-activation-deactivation-functions.patch
queue-5.4/netfilter-nft_set_rbtree-skip-sync-gc-for-new-elements-in-this-transaction.patch
queue-5.4/netfilter-nf_tables-pass-context-to-nft_set_destroy.patch
queue-5.4/netfilter-nf_tables-bogus-ebusy-when-deleting-flowtable-after-flush-for-5.4.patch
queue-5.4/netfilter-nft_set_hash-try-later-when-gc-hits-eagain-on-iteration.patch
queue-5.4/netfilter-nf_tables-defer-gc-run-if-previous-batch-is-still-pending.patch
queue-5.4/netfilter-nft_set_rbtree-use-read-spinlock-to-avoid-datapath-contention.patch
queue-5.4/netfilter-nf_tables-double-hook-unregistration-in-netns-path.patch
queue-5.4/netfilter-nftables-update-table-flags-from-the-commit-phase.patch
queue-5.4/netfilter-nft_set_hash-mark-set-element-as-dead-when-deleting-from-packet-path.patch
queue-5.4/netfilter-nf_tables-gc-transaction-api-to-avoid-race-with-control-plane.patch
queue-5.4/netfilter-nf_tables-fix-table-flag-updates.patch
queue-5.4/netfilter-nft_set_rbtree-fix-null-deref-on-element-insertion.patch
