[Jammy/Jammy-OEM-6.0/Jammy-OEM-6.1/Lunar][PATCH 1/1] netfilter: nf_tables: deactivate catchall elements in next generation

Yuxuan Luo yuxuan.luo at canonical.com
Wed Aug 30 19:45:39 UTC 2023


From: Florian Westphal <fw at strlen.de>

When flushing, individual set elements are disabled in the next
generation via the ->flush callback.

Catchall elements are not disabled.  This is incorrect and may lead to
double-deactivations of catchall elements which then results in memory
leaks:

WARNING: CPU: 1 PID: 3300 at include/net/netfilter/nf_tables.h:1172 nft_map_deactivate+0x549/0x730
CPU: 1 PID: 3300 Comm: nft Not tainted 6.5.0-rc5+ #60
RIP: 0010:nft_map_deactivate+0x549/0x730
 [..]
 ? nft_map_deactivate+0x549/0x730
 nf_tables_delset+0xb66/0xeb0

(the warn is due to nft_use_dec() detecting underflow).

Fixes: aaa31047a6d2 ("netfilter: nftables: add catch-all set element support")
Reported-by: lonial con <kongln9170 at gmail.com>
Signed-off-by: Florian Westphal <fw at strlen.de>
(cherry picked from commit 90e5b3462efa37b8bba82d7c4e63683856e188af)
CVE-2023-4569
Signed-off-by: Yuxuan Luo <yuxuan.luo at canonical.com>
---
 net/netfilter/nf_tables_api.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 6d25a2c882ef0..a78efe80ba1fa 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6778,6 +6778,7 @@ static int nft_set_catchall_flush(const struct nft_ctx *ctx,
 		ret = __nft_set_catchall_flush(ctx, set, &elem);
 		if (ret < 0)
 			break;
+		nft_set_elem_change_active(ctx->net, set, ext);
 	}
 
 	return ret;
-- 
2.34.1




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