From: Arne Fitzenreiter Date: Fri, 11 Sep 2020 19:27:15 +0000 (+0200) Subject: kernel: add patch against CVE-2020-14386 X-Git-Url: http://git.ipfire.org/?p=people%2Fpmueller%2Fipfire-2.x.git;a=commitdiff_plain;h=f04023b1ca5675ce5463ca47186462179fd7a02a kernel: add patch against CVE-2020-14386 fixes #12483 Signed-off-by: Arne Fitzenreiter --- diff --git a/lfs/linux b/lfs/linux index 2482572869..0f118455a2 100644 --- a/lfs/linux +++ b/lfs/linux @@ -144,6 +144,9 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects)) cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/linux/linux-random_try_to_actively_add_entropy.patch cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/linux/linux-4.14.x-add_timer_setup_on_stack.patch + # Patch CVE-2020-14386 + cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/linux/linux-cve-2020-14386_net_packet_fix_overflow_in_tpacket_rcv.patch + ifeq "$(KCFG)" "-kirkwood" cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/linux/linux-4.14.40-kirkwood-dtb.patch endif diff --git a/src/patches/linux/linux-cve-2020-14386_net_packet_fix_overflow_in_tpacket_rcv.patch b/src/patches/linux/linux-cve-2020-14386_net_packet_fix_overflow_in_tpacket_rcv.patch new file mode 100644 index 0000000000..439dca7ac9 --- /dev/null +++ b/src/patches/linux/linux-cve-2020-14386_net_packet_fix_overflow_in_tpacket_rcv.patch @@ -0,0 +1,54 @@ +From acf69c946233259ab4d64f8869d4037a198c7f06 Mon Sep 17 00:00:00 2001 +From: Or Cohen +Date: Thu, 3 Sep 2020 21:05:28 -0700 +Subject: net/packet: fix overflow in tpacket_rcv + +Using tp_reserve to calculate netoff can overflow as +tp_reserve is unsigned int and netoff is unsigned short. + +This may lead to macoff receving a smaller value then +sizeof(struct virtio_net_hdr), and if po->has_vnet_hdr +is set, an out-of-bounds write will occur when +calling virtio_net_hdr_from_skb. + +The bug is fixed by converting netoff to unsigned int +and checking if it exceeds USHRT_MAX. + +This addresses CVE-2020-14386 + +Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt") +Signed-off-by: Or Cohen +Signed-off-by: Eric Dumazet +Signed-off-by: Linus Torvalds +--- + net/packet/af_packet.c | 7 ++++++- + 1 file changed, 6 insertions(+), 1 deletion(-) + +diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c +index da8254e680f94..2b33e977a9059 100644 +--- a/net/packet/af_packet.c ++++ b/net/packet/af_packet.c +@@ -2170,7 +2170,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, + int skb_len = skb->len; + unsigned int snaplen, res; + unsigned long status = TP_STATUS_USER; +- unsigned short macoff, netoff, hdrlen; ++ unsigned short macoff, hdrlen; ++ unsigned int netoff; + struct sk_buff *copy_skb = NULL; + struct timespec64 ts; + __u32 ts_status; +@@ -2239,6 +2240,10 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, + } + macoff = netoff - maclen; + } ++ if (netoff > USHRT_MAX) { ++ atomic_inc(&po->tp_drops); ++ goto drop_n_restore; ++ } + if (po->tp_version <= TPACKET_V2) { + if (macoff + snaplen > po->rx_ring.frame_size) { + if (po->copy_thresh && +-- +cgit 1.2.3-1.el7 +