* [nft PATCH] libnftables: Zero ctx->vars after freeing it
@ 2024-09-03 15:49 Phil Sutter
2024-09-03 16:14 ` Phil Sutter
0 siblings, 1 reply; 2+ messages in thread
From: Phil Sutter @ 2024-09-03 15:49 UTC (permalink / raw)
To: Pablo Neira Ayuso; +Cc: netfilter-devel
Leaving the invalid pointer value in place will cause a double-free when
users call nft_ctx_clear_vars() first, then nft_ctx_free(). Moreover,
nft_ctx_add_var() passes the pointer to mrealloc() and thus assumes it
to be either NULL or valid.
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1772
Fixes: 9edaa6a51eab4 ("src: add --define key=value")
Signed-off-by: Phil Sutter <phil@nwl.cc>
---
src/libnftables.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/libnftables.c b/src/libnftables.c
index 7fc81515258d1..2ae215013cb0a 100644
--- a/src/libnftables.c
+++ b/src/libnftables.c
@@ -160,6 +160,7 @@ void nft_ctx_clear_vars(struct nft_ctx *ctx)
}
ctx->num_vars = 0;
free(ctx->vars);
+ ctx->vars = NULL;
}
EXPORT_SYMBOL(nft_ctx_add_include_path);
--
2.43.0
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