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From: Justin Stitt <justinstitt@google.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>,
	Jozsef Kadlecsik <kadlec@netfilter.org>,
	Florian Westphal <fw@strlen.de>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: linux-hardening@vger.kernel.org,
	Kees Cook <keescook@chromium.org>,
	netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Justin Stitt <justinstitt@google.com>
Subject: [PATCH 7/7] netfilter: xtables: refactor deprecated strncpy
Date: Tue, 08 Aug 2023 22:48:12 +0000	[thread overview]
Message-ID: <20230808-net-netfilter-v1-7-efbbe4ec60af@google.com> (raw)
In-Reply-To: <20230808-net-netfilter-v1-0-efbbe4ec60af@google.com>

Prefer `strscpy` as it's a more robust interface.

There may have existed a bug here due to both `tbl->repl.name` and
`info->name` having a size of 32 as defined below:
|  #define XT_TABLE_MAXNAMELEN 32

This may lead to buffer overreads in some situations -- `strscpy` solves
this by guaranteeing NUL-termination of the dest buffer.

Signed-off-by: Justin Stitt <justinstitt@google.com>

---
Note: build tested only
---
 net/netfilter/xt_repldata.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/xt_repldata.h b/net/netfilter/xt_repldata.h
index 68ccbe50bb1e..63869fd0ec57 100644
--- a/net/netfilter/xt_repldata.h
+++ b/net/netfilter/xt_repldata.h
@@ -29,7 +29,7 @@
 	if (tbl == NULL) \
 		return NULL; \
 	term = (struct type##_error *)&(((char *)tbl)[term_offset]); \
-	strncpy(tbl->repl.name, info->name, sizeof(tbl->repl.name)); \
+	strscpy(tbl->repl.name, info->name, sizeof(tbl->repl.name)); \
 	*term = (struct type##_error)typ2##_ERROR_INIT;  \
 	tbl->repl.valid_hooks = hook_mask; \
 	tbl->repl.num_entries = nhooks + 1; \

-- 
2.41.0.640.ga95def55d0-goog


  parent reply	other threads:[~2023-08-08 22:48 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-08 22:48 [PATCH 0/7] netfilter: refactor deprecated strncpy Justin Stitt
2023-08-08 22:48 ` [PATCH 1/7] netfilter: ipset: " Justin Stitt
2023-08-08 23:38   ` Florian Westphal
2023-08-09  0:00     ` Kees Cook
2023-08-08 22:48 ` [PATCH 2/7] netfilter: nf_tables: " Justin Stitt
2023-08-08 23:40   ` Florian Westphal
2023-08-09  0:41     ` Justin Stitt
2023-08-08 22:48 ` [PATCH 3/7] " Justin Stitt
2023-08-08 23:13   ` Florian Westphal
2023-08-08 22:48 ` [PATCH 4/7] netfilter: nft_meta: " Justin Stitt
2023-08-08 22:48 ` [PATCH 5/7] netfilter: nft_osf: refactor deprecated strncpy to strscpy Justin Stitt
2023-08-08 22:48 ` [PATCH 6/7] netfilter: x_tables: refactor deprecated strncpy Justin Stitt
2023-08-08 23:57   ` Florian Westphal
2023-08-09  0:04   ` Kees Cook
2023-08-08 22:48 ` Justin Stitt [this message]
2023-08-08 23:20   ` [PATCH 7/7] netfilter: xtables: " Jan Engelhardt

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