WSL2-Linux-Kernel/include/net/erspan.h

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#ifndef __LINUX_ERSPAN_H
#define __LINUX_ERSPAN_H
/*
* GRE header for ERSPAN encapsulation (8 octets [34:41]) -- 8 bytes
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |0|0|0|1|0|00000|000000000|00000| Protocol Type for ERSPAN |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Sequence Number (increments per packet per session) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Note that in the above GRE header [RFC1701] out of the C, R, K, S,
* s, Recur, Flags, Version fields only S (bit 03) is set to 1. The
* other fields are set to zero, so only a sequence number follows.
*
* ERSPAN Version 1 (Type II) header (8 octets [42:49])
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Ver | VLAN | COS | En|T| Session ID |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Reserved | Index |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*
* ERSPAN Version 2 (Type III) header (12 octets [42:49])
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Ver | VLAN | COS |BSO|T| Session ID |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Timestamp |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SGT |P| FT | Hw ID |D|Gra|O|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Platform Specific SubHeader (8 octets, optional)
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Platf ID | Platform Specific Info |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Platform Specific Info |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* GRE proto ERSPAN type II = 0x88BE, type III = 0x22EB
*/
#include <uapi/linux/erspan.h>
#define ERSPAN_VERSION 0x1 /* ERSPAN type II */
#define VER_MASK 0xf000
#define VLAN_MASK 0x0fff
#define COS_MASK 0xe000
#define EN_MASK 0x1800
#define T_MASK 0x0400
#define ID_MASK 0x03ff
#define INDEX_MASK 0xfffff
#define ERSPAN_VERSION2 0x2 /* ERSPAN type III*/
#define BSO_MASK EN_MASK
#define SGT_MASK 0xffff0000
#define P_MASK 0x8000
#define FT_MASK 0x7c00
#define HWID_MASK 0x03f0
#define DIR_MASK 0x0008
#define GRA_MASK 0x0006
#define O_MASK 0x0001
#define HWID_OFFSET 4
#define DIR_OFFSET 3
enum erspan_encap_type {
ERSPAN_ENCAP_NOVLAN = 0x0, /* originally without VLAN tag */
ERSPAN_ENCAP_ISL = 0x1, /* originally ISL encapsulated */
ERSPAN_ENCAP_8021Q = 0x2, /* originally 802.1Q encapsulated */
ERSPAN_ENCAP_INFRAME = 0x3, /* VLAN tag perserved in frame */
};
#define ERSPAN_V1_MDSIZE 4
#define ERSPAN_V2_MDSIZE 8
struct erspan_base_hdr {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 vlan_upper:4,
ver:4;
__u8 vlan:8;
__u8 session_id_upper:2,
t:1,
en:2,
cos:3;
__u8 session_id:8;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u8 ver: 4,
vlan_upper:4;
__u8 vlan:8;
__u8 cos:3,
en:2,
t:1,
session_id_upper:2;
__u8 session_id:8;
#else
#error "Please fix <asm/byteorder.h>"
#endif
};
static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id)
{
ershdr->session_id = id & 0xff;
ershdr->session_id_upper = (id >> 8) & 0x3;
}
static inline u16 get_session_id(const struct erspan_base_hdr *ershdr)
{
return (ershdr->session_id_upper << 8) + ershdr->session_id;
}
static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan)
{
ershdr->vlan = vlan & 0xff;
ershdr->vlan_upper = (vlan >> 8) & 0xf;
}
static inline u16 get_vlan(const struct erspan_base_hdr *ershdr)
{
return (ershdr->vlan_upper << 8) + ershdr->vlan;
}
static inline void set_hwid(struct erspan_md2 *md2, u8 hwid)
{
md2->hwid = hwid & 0xf;
md2->hwid_upper = (hwid >> 4) & 0x3;
}
static inline u8 get_hwid(const struct erspan_md2 *md2)
{
return (md2->hwid_upper << 4) + md2->hwid;
}
static inline int erspan_hdr_len(int version)
{
return sizeof(struct erspan_base_hdr) +
(version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE);
}
static inline u8 tos_to_cos(u8 tos)
{
u8 dscp, cos;
dscp = tos >> 2;
cos = dscp >> 3;
return cos;
}
static inline void erspan_build_header(struct sk_buff *skb,
u32 id, u32 index,
bool truncate, bool is_ipv4)
{
net: erspan: fix use-after-free When building the erspan header for either v1 or v2, the eth_hdr() does not point to the right inner packet's eth_hdr, causing kasan report use-after-free and slab-out-of-bouds read. The patch fixes the following syzkaller issues: [1] BUG: KASAN: slab-out-of-bounds in erspan_xmit+0x22d4/0x2430 net/ipv4/ip_gre.c:735 [2] BUG: KASAN: slab-out-of-bounds in erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 [3] BUG: KASAN: use-after-free in erspan_xmit+0x22d4/0x2430 net/ipv4/ip_gre.c:735 [4] BUG: KASAN: use-after-free in erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 [2] CPU: 0 PID: 3654 Comm: syzkaller377964 Not tainted 4.15.0-rc9+ #185 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440 erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 erspan_xmit+0x3b8/0x13b0 net/ipv4/ip_gre.c:740 __netdev_start_xmit include/linux/netdevice.h:4042 [inline] netdev_start_xmit include/linux/netdevice.h:4051 [inline] packet_direct_xmit+0x315/0x6b0 net/packet/af_packet.c:266 packet_snd net/packet/af_packet.c:2943 [inline] packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2968 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg+0xca/0x110 net/socket.c:648 SYSC_sendto+0x361/0x5c0 net/socket.c:1729 SyS_sendto+0x40/0x50 net/socket.c:1697 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 RIP: 0023:0xf7fcfc79 RSP: 002b:00000000ffc6976c EFLAGS: 00000286 ORIG_RAX: 0000000000000171 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020011000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020008000 RBP: 000000000000001c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre") Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN") Reported-by: syzbot+9723f2d288e49b492cf0@syzkaller.appspotmail.com Reported-by: syzbot+f0ddeb2b032a8e1d9098@syzkaller.appspotmail.com Reported-by: syzbot+f14b3703cd8d7670203f@syzkaller.appspotmail.com Reported-by: syzbot+eefa384efad8d7997f20@syzkaller.appspotmail.com Signed-off-by: William Tu <u9012063@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24 04:01:29 +03:00
struct ethhdr *eth = (struct ethhdr *)skb->data;
enum erspan_encap_type enc_type;
struct erspan_base_hdr *ershdr;
struct qtag_prefix {
__be16 eth_type;
__be16 tci;
} *qp;
u16 vlan_tci = 0;
u8 tos;
__be32 *idx;
tos = is_ipv4 ? ip_hdr(skb)->tos :
(ipv6_hdr(skb)->priority << 4) +
(ipv6_hdr(skb)->flow_lbl[0] >> 4);
enc_type = ERSPAN_ENCAP_NOVLAN;
/* If mirrored packet has vlan tag, extract tci and
* perserve vlan header in the mirrored frame.
*/
if (eth->h_proto == htons(ETH_P_8021Q)) {
qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
vlan_tci = ntohs(qp->tci);
enc_type = ERSPAN_ENCAP_INFRAME;
}
skb_push(skb, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
ershdr = (struct erspan_base_hdr *)skb->data;
memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
/* Build base header */
ershdr->ver = ERSPAN_VERSION;
ershdr->cos = tos_to_cos(tos);
ershdr->en = enc_type;
ershdr->t = truncate;
set_vlan(ershdr, vlan_tci);
set_session_id(ershdr, id);
/* Build metadata */
idx = (__be32 *)(ershdr + 1);
*idx = htonl(index & INDEX_MASK);
}
/* ERSPAN GRA: timestamp granularity
* 00b --> granularity = 100 microseconds
* 01b --> granularity = 100 nanoseconds
* 10b --> granularity = IEEE 1588
* Here we only support 100 microseconds.
*/
static inline __be32 erspan_get_timestamp(void)
{
u64 h_usecs;
ktime_t kt;
kt = ktime_get_real();
h_usecs = ktime_divns(kt, 100 * NSEC_PER_USEC);
/* ERSPAN base header only has 32-bit,
* so it wraps around 4 days.
*/
return htonl((u32)h_usecs);
}
/* ERSPAN BSO (Bad/Short/Oversized), see RFC1757
* 00b --> Good frame with no error, or unknown integrity
* 01b --> Payload is a Short Frame
* 10b --> Payload is an Oversized Frame
* 11b --> Payload is a Bad Frame with CRC or Alignment Error
*/
enum erspan_bso {
BSO_NOERROR = 0x0,
BSO_SHORT = 0x1,
BSO_OVERSIZED = 0x2,
BSO_BAD = 0x3,
};
static inline u8 erspan_detect_bso(struct sk_buff *skb)
{
/* BSO_BAD is not handled because the frame CRC
* or alignment error information is in FCS.
*/
if (skb->len < ETH_ZLEN)
return BSO_SHORT;
if (skb->len > ETH_FRAME_LEN)
return BSO_OVERSIZED;
return BSO_NOERROR;
}
static inline void erspan_build_header_v2(struct sk_buff *skb,
u32 id, u8 direction, u16 hwid,
bool truncate, bool is_ipv4)
{
net: erspan: fix use-after-free When building the erspan header for either v1 or v2, the eth_hdr() does not point to the right inner packet's eth_hdr, causing kasan report use-after-free and slab-out-of-bouds read. The patch fixes the following syzkaller issues: [1] BUG: KASAN: slab-out-of-bounds in erspan_xmit+0x22d4/0x2430 net/ipv4/ip_gre.c:735 [2] BUG: KASAN: slab-out-of-bounds in erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 [3] BUG: KASAN: use-after-free in erspan_xmit+0x22d4/0x2430 net/ipv4/ip_gre.c:735 [4] BUG: KASAN: use-after-free in erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 [2] CPU: 0 PID: 3654 Comm: syzkaller377964 Not tainted 4.15.0-rc9+ #185 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440 erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 erspan_xmit+0x3b8/0x13b0 net/ipv4/ip_gre.c:740 __netdev_start_xmit include/linux/netdevice.h:4042 [inline] netdev_start_xmit include/linux/netdevice.h:4051 [inline] packet_direct_xmit+0x315/0x6b0 net/packet/af_packet.c:266 packet_snd net/packet/af_packet.c:2943 [inline] packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2968 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg+0xca/0x110 net/socket.c:648 SYSC_sendto+0x361/0x5c0 net/socket.c:1729 SyS_sendto+0x40/0x50 net/socket.c:1697 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 RIP: 0023:0xf7fcfc79 RSP: 002b:00000000ffc6976c EFLAGS: 00000286 ORIG_RAX: 0000000000000171 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020011000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020008000 RBP: 000000000000001c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre") Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN") Reported-by: syzbot+9723f2d288e49b492cf0@syzkaller.appspotmail.com Reported-by: syzbot+f0ddeb2b032a8e1d9098@syzkaller.appspotmail.com Reported-by: syzbot+f14b3703cd8d7670203f@syzkaller.appspotmail.com Reported-by: syzbot+eefa384efad8d7997f20@syzkaller.appspotmail.com Signed-off-by: William Tu <u9012063@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24 04:01:29 +03:00
struct ethhdr *eth = (struct ethhdr *)skb->data;
struct erspan_base_hdr *ershdr;
struct erspan_md2 *md2;
struct qtag_prefix {
__be16 eth_type;
__be16 tci;
} *qp;
u16 vlan_tci = 0;
u8 gra = 0; /* 100 usec */
u8 bso = 0; /* Bad/Short/Oversized */
u8 sgt = 0;
u8 tos;
tos = is_ipv4 ? ip_hdr(skb)->tos :
(ipv6_hdr(skb)->priority << 4) +
(ipv6_hdr(skb)->flow_lbl[0] >> 4);
/* Unlike v1, v2 does not have En field,
* so only extract vlan tci field.
*/
if (eth->h_proto == htons(ETH_P_8021Q)) {
qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
vlan_tci = ntohs(qp->tci);
}
bso = erspan_detect_bso(skb);
skb_push(skb, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
ershdr = (struct erspan_base_hdr *)skb->data;
memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
/* Build base header */
ershdr->ver = ERSPAN_VERSION2;
ershdr->cos = tos_to_cos(tos);
ershdr->en = bso;
ershdr->t = truncate;
set_vlan(ershdr, vlan_tci);
set_session_id(ershdr, id);
/* Build metadata */
md2 = (struct erspan_md2 *)(ershdr + 1);
md2->timestamp = erspan_get_timestamp();
md2->sgt = htons(sgt);
md2->p = 1;
md2->ft = 0;
md2->dir = direction;
md2->gra = gra;
md2->o = 0;
set_hwid(md2, hwid);
}
#endif