40 lines
1.2 KiB
Diff
40 lines
1.2 KiB
Diff
From: Felix Fietkau <nbd@nbd.name>
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Date: Sat, 19 Nov 2022 18:48:42 +0100
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Subject: [PATCH] netfilter: nf_flow_table: add missing locking
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nf_flow_table_block_setup and the driver TC_SETUP_FT call can modify the flow
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block cb list while they are being traversed elsewhere, causing a crash.
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Add a write lock around the calls to protect readers
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Signed-off-by: Felix Fietkau <nbd@nbd.name>
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---
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--- a/net/netfilter/nf_flow_table_offload.c
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+++ b/net/netfilter/nf_flow_table_offload.c
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@@ -1015,6 +1015,7 @@ static int nf_flow_table_block_setup(str
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struct flow_block_cb *block_cb, *next;
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int err = 0;
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+ down_write(&flowtable->flow_block_lock);
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switch (cmd) {
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case FLOW_BLOCK_BIND:
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list_splice(&bo->cb_list, &flowtable->flow_block.cb_list);
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@@ -1029,6 +1030,7 @@ static int nf_flow_table_block_setup(str
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WARN_ON_ONCE(1);
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err = -EOPNOTSUPP;
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}
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+ up_write(&flowtable->flow_block_lock);
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return err;
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}
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@@ -1085,7 +1087,9 @@ static int nf_flow_table_offload_cmd(str
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nf_flow_table_block_offload_init(bo, dev_net(dev), cmd, flowtable,
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extack);
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+ down_write(&flowtable->flow_block_lock);
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err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_FT, bo);
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+ up_write(&flowtable->flow_block_lock);
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if (err < 0)
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return err;
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