From: Joel Savitz Subject: [KPATCH 7.9] netfilter: x_tables: kpatch fixes for CVE-2021-22555 Date: Wed, 28 Jul 2021 12:03:15 -0400 Kernels: 3.10.0-1160.el7 3.10.0-1160.2.1.el7 3.10.0-1160.2.2.el7 3.10.0-1160.6.1.el7 3.10.0-1160.11.1.el7 3.10.0-1160.15.2.el7 3.10.0-1160.21.1.el7 3.10.0-1160.24.1.el7 3.10.0-1160.25.1.el7 3.10.0-1160.31.1.el7 3.10.0-1160.36.2.el7 Changes since last build: arches: x86_64 ppc64le arp_tables.o: changed function: translate_compat_table ip6_tables.o: changed function: translate_compat_table ip_tables.o: changed function: translate_compat_table x_tables.o: changed function: xt_compat_match_from_user x_tables.o: changed function: xt_compat_target_from_user --------------------------- Kernels: 3.10.0-1160.el7 3.10.0-1160.2.1.el7 3.10.0-1160.2.2.el7 3.10.0-1160.6.1.el7 3.10.0-1160.11.1.el7 3.10.0-1160.15.2.el7 3.10.0-1160.21.1.el7 3.10.0-1160.24.1.el7 3.10.0-1160.25.1.el7 3.10.0-1160.31.1.el7 3.10.0-1160.36.2.el7 Modifications: none Z-MR: https://gitlab.com/redhat/rhel/src/kernel/rhel-7/-/merge_requests/201 KT0 test PASS: https://beaker.engineering.redhat.com/jobs/5642298 for scratch build: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=38448253 commit 06215319786b979bed0f5eb3138de0506db9d39f Author: Florian Westphal Date: Fri Jul 9 11:42:55 2021 +0200 netfilter: x_tables: fix compat match/target pad out-of-bound write Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1980489 Upstream Status: commit b29c457a65114 CVE: CVE-2021-22555 commit b29c457a6511435960115c0f548c4360d5f4801d Author: Florian Westphal Date: Wed Apr 7 21:38:57 2021 +0200 netfilter: x_tables: fix compat match/target pad out-of-bound write 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 Fixes: 9fa492cdc160c ("[NETFILTER]: x_tables: simplify compat API") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal Signed-off-by: Joel Savitz Acked-by: Joe Lawrence Acked-by: Artem Savkov Acked-by: Yannick Cote --- 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(-) diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 602d92697038..66ad3b4e194c 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -1364,6 +1364,8 @@ static int translate_compat_table(struct xt_table_info **pinfo, 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] = info->hook_entry[i]; diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 3559f7ffa430..d9de653be67e 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1622,6 +1622,8 @@ 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]; diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 1772a1797e79..d112bfc86aac 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1626,6 +1626,8 @@ 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]; diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 76e40ff48b10..affd08ce7df8 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -564,7 +564,7 @@ void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, { 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)]; @@ -574,9 +574,6 @@ void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, 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; @@ -913,7 +910,7 @@ void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr, { 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)]; @@ -923,9 +920,6 @@ void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr, 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; -- 2.27.0