From: Felix Fietkau Date: Mon, 21 Nov 2022 18:26:15 +0000 (+0100) Subject: netfilter: flowtable_offload: add missing locking X-Git-Tag: v5.10.157~82 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b8e494240e69f91517256adcd6fda62d0671772d;p=thirdparty%2Fkernel%2Fstable.git netfilter: flowtable_offload: add missing locking [ Upstream commit bcd9e3c1656d0f7dd9743598c65c3ae24efb38d0 ] nf_flow_table_block_setup and the driver TC_SETUP_FT call can modify the flow block cb list while they are being traversed elsewhere, causing a crash. Add a write lock around the calls to protect readers Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support") Reported-by: Chad Monroe Signed-off-by: Felix Fietkau Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c index d1862782be450..28306cb667190 100644 --- a/net/netfilter/nf_flow_table_offload.c +++ b/net/netfilter/nf_flow_table_offload.c @@ -910,6 +910,7 @@ static int nf_flow_table_block_setup(struct nf_flowtable *flowtable, struct flow_block_cb *block_cb, *next; int err = 0; + down_write(&flowtable->flow_block_lock); switch (cmd) { case FLOW_BLOCK_BIND: list_splice(&bo->cb_list, &flowtable->flow_block.cb_list); @@ -924,6 +925,7 @@ static int nf_flow_table_block_setup(struct nf_flowtable *flowtable, WARN_ON_ONCE(1); err = -EOPNOTSUPP; } + up_write(&flowtable->flow_block_lock); return err; } @@ -980,7 +982,9 @@ static int nf_flow_table_offload_cmd(struct flow_block_offload *bo, nf_flow_table_block_offload_init(bo, dev_net(dev), cmd, flowtable, extack); + down_write(&flowtable->flow_block_lock); err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_FT, bo); + up_write(&flowtable->flow_block_lock); if (err < 0) return err;