FAILED: patch "[PATCH] netfilter: ebtables: zero chainstack array" failed to apply to 6.12-stable tree

FAILED: patch "[PATCH] netfilter: ebtables: zero chainstack array" failed to apply to 6.12-stable tree

[gregkh]

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x cbfe53599eebffd188938ab6774cc41794f6f9d5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071334-dribble-bunny-03b1@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From cbfe53599eebffd188938ab6774cc41794f6f9d5 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Sat, 4 Jul 2026 10:23:31 +0200
Subject: [PATCH] netfilter: ebtables: zero chainstack array

sashiko reports:
 looking at ebtables table
 translation, could a sparse cpu_possible_mask lead to an uninitialized pointer
 free?

 If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible,
 but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at
 CPU 2, the cleanup loop will blindly decrement and call vfree() on
 newinfo->chainstack[1].

Not a real-world bug, such allocation isn't expected to fail
in the first place.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 5b74ff827493..48187598cdd0 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -921,8 +921,7 @@ static int translate_table(struct net *net, const char *name,
 		 * if an error occurs
 		 */
 		newinfo->chainstack =
-			vmalloc_array(nr_cpu_ids,
-				      sizeof(*(newinfo->chainstack)));
+			vcalloc(nr_cpu_ids, sizeof(*(newinfo->chainstack)));
 		if (!newinfo->chainstack)
 			return -ENOMEM;
 		for_each_possible_cpu(i) {

[PATCH 6.12.y 1/2] netfilter: ebtables: Use vmalloc_array() to improve code

[Sasha Levin]

From: Qianfeng Rong <rongqianfeng@vivo.com>

[ Upstream commit 46015e6b3ea75297b28d4806564f3f692cf11861 ]

Remove array_size() calls and replace vmalloc() with vmalloc_array() to
simplify the code.  vmalloc_array() is also optimized better, uses fewer
instructions, and handles overflow more concisely[1].

[1]: https://lore.kernel.org/lkml/abc66ec5-85a4-47e1-9759-2f60ab111971@vivo.com/
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: cbfe53599eeb ("netfilter: ebtables: zero chainstack array")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bridge/netfilter/ebtables.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 1bc7b5d8f76d7a..d8dda76ac14524 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -920,8 +920,8 @@ static int translate_table(struct net *net, const char *name,
 		 * if an error occurs
 		 */
 		newinfo->chainstack =
-			vmalloc(array_size(nr_cpu_ids,
-					   sizeof(*(newinfo->chainstack))));
+			vmalloc_array(nr_cpu_ids,
+				      sizeof(*(newinfo->chainstack)));
 		if (!newinfo->chainstack)
 			return -ENOMEM;
 		for_each_possible_cpu(i) {
@@ -938,7 +938,7 @@ static int translate_table(struct net *net, const char *name,
 			}
 		}
 
-		cl_s = vmalloc(array_size(udc_cnt, sizeof(*cl_s)));
+		cl_s = vmalloc_array(udc_cnt, sizeof(*cl_s));
 		if (!cl_s)
 			return -ENOMEM;
 		i = 0; /* the i'th udc */
@@ -1018,8 +1018,8 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl,
 	 * the check on the size is done later, when we have the lock
 	 */
 	if (repl->num_counters) {
-		unsigned long size = repl->num_counters * sizeof(*counterstmp);
-		counterstmp = vmalloc(size);
+		counterstmp = vmalloc_array(repl->num_counters,
+					    sizeof(*counterstmp));
 		if (!counterstmp)
 			return -ENOMEM;
 	}
@@ -1386,7 +1386,7 @@ static int do_update_counters(struct net *net, const char *name,
 	if (num_counters == 0)
 		return -EINVAL;
 
-	tmp = vmalloc(array_size(num_counters, sizeof(*tmp)));
+	tmp = vmalloc_array(num_counters, sizeof(*tmp));
 	if (!tmp)
 		return -ENOMEM;
 
@@ -1526,7 +1526,7 @@ static int copy_counters_to_user(struct ebt_table *t,
 	if (num_counters != nentries)
 		return -EINVAL;
 
-	counterstmp = vmalloc(array_size(nentries, sizeof(*counterstmp)));
+	counterstmp = vmalloc_array(nentries, sizeof(*counterstmp));
 	if (!counterstmp)
 		return -ENOMEM;
 
-- 
2.53.0

[PATCH 6.12.y 2/2] netfilter: ebtables: zero chainstack array

[Sasha Levin]

From: Florian Westphal <fw@strlen.de>

[ Upstream commit cbfe53599eebffd188938ab6774cc41794f6f9d5 ]

sashiko reports:
 looking at ebtables table
 translation, could a sparse cpu_possible_mask lead to an uninitialized pointer
 free?

 If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible,
 but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at
 CPU 2, the cleanup loop will blindly decrement and call vfree() on
 newinfo->chainstack[1].

Not a real-world bug, such allocation isn't expected to fail
in the first place.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bridge/netfilter/ebtables.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index d8dda76ac14524..7417d46af4b2b8 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -920,8 +920,7 @@ static int translate_table(struct net *net, const char *name,
 		 * if an error occurs
 		 */
 		newinfo->chainstack =
-			vmalloc_array(nr_cpu_ids,
-				      sizeof(*(newinfo->chainstack)));
+			vcalloc(nr_cpu_ids, sizeof(*(newinfo->chainstack)));
 		if (!newinfo->chainstack)
 			return -ENOMEM;
 		for_each_possible_cpu(i) {
-- 
2.53.0