On Tue, 2 Jul 2024 16:08:14 +0200 Florian Westphal <fw@xxxxxxxxx> > syzbot reports: > > KASAN: slab-uaf in nft_ctx_update include/net/netfilter/nf_tables.h:1831 > KASAN: slab-uaf in nft_commit_release net/netfilter/nf_tables_api.c:9530 > KASAN: slab-uaf int nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597 > Read of size 2 at addr ffff88802b0051c4 by task kworker/1:1/45 > [..] > Workqueue: events nf_tables_trans_destroy_work > Call Trace: > nft_ctx_update include/net/netfilter/nf_tables.h:1831 [inline] > nft_commit_release net/netfilter/nf_tables_api.c:9530 [inline] > nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597 > > Problem is that the notifier does a conditional flush, but its possible > that the table-to-be-removed is still referenced by transactions being > processed by the worker, so we need to flush unconditionally. > Given trans->table goes thru the lifespan of trans, your proposal is a bandaid if trans outlives table.
