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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com,
	Andy Nguyen <theflow@google.com>, Florian Westphal <fw@strlen.de>,
	Pablo Neira Ayuso <pablo@netfilter.org>
Subject: [PATCH 5.10 21/25] netfilter: x_tables: fix compat match/target pad out-of-bound write
Date: Thu, 15 Apr 2021 16:48:15 +0200	[thread overview]
Message-ID: <20210415144413.825167856@linuxfoundation.org> (raw)
In-Reply-To: <20210415144413.165663182@linuxfoundation.org>

From: Florian Westphal <fw@strlen.de>

commit b29c457a6511435960115c0f548c4360d5f4801d upstream.

xt_compat_match/target_from_user doesn't check that zeroing the area
to start of next rule won't write past end of allocated ruleset blob.

Remove this code and zero the entire blob beforehand.

Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com
Reported-by: Andy Nguyen <theflow@google.com>
Fixes: 9fa492cdc160c ("[NETFILTER]: x_tables: simplify compat API")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/netfilter/arp_tables.c |    2 ++
 net/ipv4/netfilter/ip_tables.c  |    2 ++
 net/ipv6/netfilter/ip6_tables.c |    2 ++
 net/netfilter/x_tables.c        |   10 ++--------
 4 files changed, 8 insertions(+), 8 deletions(-)

--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1193,6 +1193,8 @@ static int translate_compat_table(struct
 	if (!newinfo)
 		goto out_unlock;
 
+	memset(newinfo->entries, 0, size);
+
 	newinfo->number = compatr->num_entries;
 	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 		newinfo->hook_entry[i] = compatr->hook_entry[i];
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1428,6 +1428,8 @@ translate_compat_table(struct net *net,
 	if (!newinfo)
 		goto out_unlock;
 
+	memset(newinfo->entries, 0, size);
+
 	newinfo->number = compatr->num_entries;
 	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 		newinfo->hook_entry[i] = compatr->hook_entry[i];
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1443,6 +1443,8 @@ translate_compat_table(struct net *net,
 	if (!newinfo)
 		goto out_unlock;
 
+	memset(newinfo->entries, 0, size);
+
 	newinfo->number = compatr->num_entries;
 	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 		newinfo->hook_entry[i] = compatr->hook_entry[i];
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -733,7 +733,7 @@ void xt_compat_match_from_user(struct xt
 {
 	const struct xt_match *match = m->u.kernel.match;
 	struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
-	int pad, off = xt_compat_match_offset(match);
+	int off = xt_compat_match_offset(match);
 	u_int16_t msize = cm->u.user.match_size;
 	char name[sizeof(m->u.user.name)];
 
@@ -743,9 +743,6 @@ void xt_compat_match_from_user(struct xt
 		match->compat_from_user(m->data, cm->data);
 	else
 		memcpy(m->data, cm->data, msize - sizeof(*cm));
-	pad = XT_ALIGN(match->matchsize) - match->matchsize;
-	if (pad > 0)
-		memset(m->data + match->matchsize, 0, pad);
 
 	msize += off;
 	m->u.user.match_size = msize;
@@ -1116,7 +1113,7 @@ void xt_compat_target_from_user(struct x
 {
 	const struct xt_target *target = t->u.kernel.target;
 	struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
-	int pad, off = xt_compat_target_offset(target);
+	int off = xt_compat_target_offset(target);
 	u_int16_t tsize = ct->u.user.target_size;
 	char name[sizeof(t->u.user.name)];
 
@@ -1126,9 +1123,6 @@ void xt_compat_target_from_user(struct x
 		target->compat_from_user(t->data, ct->data);
 	else
 		memcpy(t->data, ct->data, tsize - sizeof(*ct));
-	pad = XT_ALIGN(target->targetsize) - target->targetsize;
-	if (pad > 0)
-		memset(t->data + target->targetsize, 0, pad);
 
 	tsize += off;
 	t->u.user.target_size = tsize;



  parent reply	other threads:[~2021-04-15 15:12 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-15 14:47 [PATCH 5.10 00/25] 5.10.31-rc1 review Greg Kroah-Hartman
2021-04-15 14:47 ` [PATCH 5.10 01/25] interconnect: core: fix error return code of icc_link_destroy() Greg Kroah-Hartman
2021-04-15 14:47 ` [PATCH 5.10 02/25] gfs2: Flag a withdraw if init_threads() fails Greg Kroah-Hartman
2021-04-15 14:47 ` [PATCH 5.10 03/25] KVM: arm64: Hide system instruction access to Trace registers Greg Kroah-Hartman
2021-04-15 14:47 ` [PATCH 5.10 04/25] KVM: arm64: Disable guest access to trace filter controls Greg Kroah-Hartman
2021-04-15 14:47 ` [PATCH 5.10 05/25] drm/imx: imx-ldb: fix out of bounds array access warning Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 06/25] gfs2: report "already frozen/thawed" errors Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 07/25] ftrace: Check if pages were allocated before calling free_pages() Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 08/25] tools/kvm_stat: Add restart delay Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 09/25] drm/tegra: dc: Dont set PLL clock to 0Hz Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 10/25] gpu: host1x: Use different lock classes for each client Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 11/25] XArray: Fix splitting to non-zero orders Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 12/25] radix tree test suite: Fix compilation Greg Kroah-Hartman
2021-04-15 15:12   ` Matthew Wilcox
2021-04-16  0:06     ` Sasha Levin
2021-04-15 14:48 ` [PATCH 5.10 13/25] block: only update parent bi_status when bio fail Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 14/25] radix tree test suite: Register the main thread with the RCU library Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 15/25] idr test suite: Take RCU read lock in idr_find_test_1 Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 16/25] idr test suite: Create anchor before launching throbber Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 17/25] null_blk: fix command timeout completion handling Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 18/25] io_uring: dont mark S_ISBLK async work as unbounded Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 19/25] riscv,entry: fix misaligned base for excp_vect_table Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 20/25] block: dont ignore REQ_NOWAIT for direct IO Greg Kroah-Hartman
2021-04-15 14:48 ` Greg Kroah-Hartman [this message]
2021-04-15 14:48 ` [PATCH 5.10 22/25] perf map: Tighten snprintf() string precision to pass gcc check on some 32-bit arches Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 23/25] net: sfp: relax bitrate-derived mode check Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 24/25] net: sfp: cope with SFPs that set both LOS normal and LOS inverted Greg Kroah-Hartman
2021-04-15 14:48 ` [PATCH 5.10 25/25] xen/events: fix setting irq affinity Greg Kroah-Hartman
2021-04-15 19:11 ` [PATCH 5.10 00/25] 5.10.31-rc1 review Pavel Machek
2021-04-15 20:03 ` Andrei Rabusov
2021-04-15 22:42 ` Shuah Khan
2021-04-16  0:52 ` Florian Fainelli
2021-04-16  9:38 ` Naresh Kamboju
2021-04-16 19:57 ` Fox Chen
2021-04-16 20:07 ` Sudip Mukherjee
2021-04-17  1:01 ` Samuel Zou

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