From: Xin Long lucien.xin@gmail.com
[ Upstream commit b6f3320b1d5267e7b583a6d0c88dda518101740c ]
Syzbot found a crash:
BUG: KMSAN: uninit-value in crc32_body lib/crc32.c:112 [inline] BUG: KMSAN: uninit-value in crc32_le_generic lib/crc32.c:179 [inline] BUG: KMSAN: uninit-value in __crc32c_le_base+0x4fa/0xd30 lib/crc32.c:202 Call Trace: crc32_body lib/crc32.c:112 [inline] crc32_le_generic lib/crc32.c:179 [inline] __crc32c_le_base+0x4fa/0xd30 lib/crc32.c:202 chksum_update+0xb2/0x110 crypto/crc32c_generic.c:90 crypto_shash_update+0x4c5/0x530 crypto/shash.c:107 crc32c+0x150/0x220 lib/libcrc32c.c:47 sctp_csum_update+0x89/0xa0 include/net/sctp/checksum.h:36 __skb_checksum+0x1297/0x12a0 net/core/skbuff.c:2640 sctp_compute_cksum include/net/sctp/checksum.h:59 [inline] sctp_packet_pack net/sctp/output.c:528 [inline] sctp_packet_transmit+0x40fb/0x4250 net/sctp/output.c:597 sctp_outq_flush_transports net/sctp/outqueue.c:1146 [inline] sctp_outq_flush+0x1823/0x5d80 net/sctp/outqueue.c:1194 sctp_outq_uncork+0xd0/0xf0 net/sctp/outqueue.c:757 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1781 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1184 [inline] sctp_do_sm+0x8fe1/0x9720 net/sctp/sm_sideeffect.c:1155 sctp_primitive_REQUESTHEARTBEAT+0x175/0x1a0 net/sctp/primitive.c:185 sctp_apply_peer_addr_params+0x212/0x1d40 net/sctp/socket.c:2433 sctp_setsockopt_peer_addr_params net/sctp/socket.c:2686 [inline] sctp_setsockopt+0x189bb/0x19090 net/sctp/socket.c:4672
The issue was caused by transport->ipaddr set with uninit addr param, which was passed by:
sctp_transport_init net/sctp/transport.c:47 [inline] sctp_transport_new+0x248/0xa00 net/sctp/transport.c:100 sctp_assoc_add_peer+0x5ba/0x2030 net/sctp/associola.c:611 sctp_process_param net/sctp/sm_make_chunk.c:2524 [inline]
where 'addr' is set by sctp_v4_from_addr_param(), and it doesn't initialize the padding of addr->v4.
Later when calling sctp_make_heartbeat(), hbinfo.daddr(=transport->ipaddr) will become the part of skb, and the issue occurs.
This patch is to fix it by initializing the padding of addr->v4 in sctp_v4_from_addr_param(), as well as other functions that do the similar thing, and these functions shouldn't trust that the caller initializes the memory, as Marcelo suggested.
Reported-by: syzbot+6dcbfea81cd3d4dd0b02@syzkaller.appspotmail.com Signed-off-by: Xin Long lucien.xin@gmail.com Acked-by: Neil Horman nhorman@tuxdriver.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sctp/protocol.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -242,6 +242,7 @@ static void sctp_v4_from_skb(union sctp_ sa->sin_port = sh->dest; sa->sin_addr.s_addr = ip_hdr(skb)->daddr; } + memset(sa->sin_zero, 0, sizeof(sa->sin_zero)); }
/* Initialize an sctp_addr from a socket. */ @@ -250,6 +251,7 @@ static void sctp_v4_from_sk(union sctp_a addr->v4.sin_family = AF_INET; addr->v4.sin_port = 0; addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr; + memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); }
/* Initialize sk->sk_rcv_saddr from sctp_addr. */ @@ -272,6 +274,7 @@ static void sctp_v4_from_addr_param(unio addr->v4.sin_family = AF_INET; addr->v4.sin_port = port; addr->v4.sin_addr.s_addr = param->v4.addr.s_addr; + memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); }
/* Initialize an address parameter from a sctp_addr and return the length @@ -296,6 +299,7 @@ static void sctp_v4_dst_saddr(union sctp saddr->v4.sin_family = AF_INET; saddr->v4.sin_port = port; saddr->v4.sin_addr.s_addr = fl4->saddr; + memset(saddr->v4.sin_zero, 0, sizeof(saddr->v4.sin_zero)); }
/* Compare two addresses exactly. */ @@ -318,6 +322,7 @@ static void sctp_v4_inaddr_any(union sct addr->v4.sin_family = AF_INET; addr->v4.sin_addr.s_addr = htonl(INADDR_ANY); addr->v4.sin_port = port; + memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); }
/* Is this a wildcard address? */