From: Wander Lairson Costa wander@redhat.com

stable inclusion from stable-v5.10.195 commit 5541827d13cf19b905594eaee586527476efaa61 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I85CAQ CVE: CVE-2023-39193

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit e99476497687ef9e850748fe6d232264f30bc8f9 upstream.

sctp_mt_check doesn't validate the flag_count field. An attacker can take advantage of that to trigger a OOB read and leak memory information.

Add the field validation in the checkentry function.

Fixes: 2e4e6a17af35 ("[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables") Cc: stable@vger.kernel.org Reported-by: Lucas Leong wmliang@infosec.exchange Signed-off-by: Wander Lairson Costa wander@redhat.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com --- net/netfilter/xt_sctp.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/net/netfilter/xt_sctp.c b/net/netfilter/xt_sctp.c index 680015ba7cb6..d4bf089c9e3f 100644 --- a/net/netfilter/xt_sctp.c +++ b/net/netfilter/xt_sctp.c @@ -150,6 +150,8 @@ static int sctp_mt_check(const struct xt_mtchk_param *par) { const struct xt_sctp_info *info = par->matchinfo;

+ if (info->flag_count > ARRAY_SIZE(info->flag_info)) + return -EINVAL; if (info->flags & ~XT_SCTP_VALID_FLAGS) return -EINVAL; if (info->invflags & ~XT_SCTP_VALID_FLAGS)