From 9e9714742fb70467464359693a73b911a630226f Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Thu, 25 Mar 2021 13:58:48 +0100 Subject: [PATCH 1/3] can: bcm/raw: fix msg_namelen values depending on CAN_REQUIRED_SIZE Since commit f5223e9eee65 ("can: extend sockaddr_can to include j1939 members") the sockaddr_can has been extended in size and a new CAN_REQUIRED_SIZE macro has been introduced to calculate the protocol specific needed size. The ABI for the msg_name and msg_namelen has not been adapted to the new CAN_REQUIRED_SIZE macro for the other CAN protocols which leads to a problem when an existing binary reads the (increased) struct sockaddr_can in msg_name. Fixes: f5223e9eee65 ("can: extend sockaddr_can to include j1939 members") Reported-by: Richard Weinberger Tested-by: Richard Weinberger Acked-by: Kurt Van Dijck Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t Link: https://lore.kernel.org/r/20210325125850.1620-1-socketcan@hartkopp.net Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- net/can/bcm.c | 10 ++++++---- net/can/raw.c | 14 ++++++++------ 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/net/can/bcm.c b/net/can/bcm.c index 0e5c37be4a2b..909b9e684e04 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -86,6 +86,8 @@ MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Oliver Hartkopp "); MODULE_ALIAS("can-proto-2"); +#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex) + /* * easy access to the first 64 bit of can(fd)_frame payload. cp->data is * 64 bit aligned so the offset has to be multiples of 8 which is ensured @@ -1292,7 +1294,7 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) /* no bound device as default => check msg_name */ DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); - if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex)) + if (msg->msg_namelen < BCM_MIN_NAMELEN) return -EINVAL; if (addr->can_family != AF_CAN) @@ -1534,7 +1536,7 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, struct net *net = sock_net(sk); int ret = 0; - if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex)) + if (len < BCM_MIN_NAMELEN) return -EINVAL; lock_sock(sk); @@ -1616,8 +1618,8 @@ static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, sock_recv_ts_and_drops(msg, sk, skb); if (msg->msg_name) { - __sockaddr_check_size(sizeof(struct sockaddr_can)); - msg->msg_namelen = sizeof(struct sockaddr_can); + __sockaddr_check_size(BCM_MIN_NAMELEN); + msg->msg_namelen = BCM_MIN_NAMELEN; memcpy(msg->msg_name, skb->cb, msg->msg_namelen); } diff --git a/net/can/raw.c b/net/can/raw.c index 37b47a39a3ed..139d9471ddcf 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -60,6 +60,8 @@ MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Urs Thuermann "); MODULE_ALIAS("can-proto-1"); +#define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex) + #define MASK_ALL 0 /* A raw socket has a list of can_filters attached to it, each receiving @@ -394,7 +396,7 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) int err = 0; int notify_enetdown = 0; - if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex)) + if (len < RAW_MIN_NAMELEN) return -EINVAL; if (addr->can_family != AF_CAN) return -EINVAL; @@ -475,11 +477,11 @@ static int raw_getname(struct socket *sock, struct sockaddr *uaddr, if (peer) return -EOPNOTSUPP; - memset(addr, 0, sizeof(*addr)); + memset(addr, 0, RAW_MIN_NAMELEN); addr->can_family = AF_CAN; addr->can_ifindex = ro->ifindex; - return sizeof(*addr); + return RAW_MIN_NAMELEN; } static int raw_setsockopt(struct socket *sock, int level, int optname, @@ -739,7 +741,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) if (msg->msg_name) { DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); - if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex)) + if (msg->msg_namelen < RAW_MIN_NAMELEN) return -EINVAL; if (addr->can_family != AF_CAN) @@ -832,8 +834,8 @@ static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, sock_recv_ts_and_drops(msg, sk, skb); if (msg->msg_name) { - __sockaddr_check_size(sizeof(struct sockaddr_can)); - msg->msg_namelen = sizeof(struct sockaddr_can); + __sockaddr_check_size(RAW_MIN_NAMELEN); + msg->msg_namelen = RAW_MIN_NAMELEN; memcpy(msg->msg_name, skb->cb, msg->msg_namelen); } From f522d9559b07854c231cf8f0b8cb5a3578f8b44e Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Thu, 25 Mar 2021 13:58:49 +0100 Subject: [PATCH 2/3] can: isotp: fix msg_namelen values depending on CAN_REQUIRED_SIZE Since commit f5223e9eee65 ("can: extend sockaddr_can to include j1939 members") the sockaddr_can has been extended in size and a new CAN_REQUIRED_SIZE macro has been introduced to calculate the protocol specific needed size. The ABI for the msg_name and msg_namelen has not been adapted to the new CAN_REQUIRED_SIZE macro for the other CAN protocols which leads to a problem when an existing binary reads the (increased) struct sockaddr_can in msg_name. Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol") Reported-by: Richard Weinberger Acked-by: Kurt Van Dijck Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t Link: https://lore.kernel.org/r/20210325125850.1620-2-socketcan@hartkopp.net Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- net/can/isotp.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/can/isotp.c b/net/can/isotp.c index 15ea1234d457..9f94ad3caee9 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -77,6 +77,8 @@ MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Oliver Hartkopp "); MODULE_ALIAS("can-proto-6"); +#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp) + #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \ (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) @@ -986,7 +988,8 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, sock_recv_timestamp(msg, sk, skb); if (msg->msg_name) { - msg->msg_namelen = sizeof(struct sockaddr_can); + __sockaddr_check_size(ISOTP_MIN_NAMELEN); + msg->msg_namelen = ISOTP_MIN_NAMELEN; memcpy(msg->msg_name, skb->cb, msg->msg_namelen); } @@ -1056,7 +1059,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) int notify_enetdown = 0; int do_rx_reg = 1; - if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)) + if (len < ISOTP_MIN_NAMELEN) return -EINVAL; /* do not register frame reception for functional addressing */ @@ -1152,13 +1155,13 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer) if (peer) return -EOPNOTSUPP; - memset(addr, 0, sizeof(*addr)); + memset(addr, 0, ISOTP_MIN_NAMELEN); addr->can_family = AF_CAN; addr->can_ifindex = so->ifindex; addr->can_addr.tp.rx_id = so->rxid; addr->can_addr.tp.tx_id = so->txid; - return sizeof(*addr); + return ISOTP_MIN_NAMELEN; } static int isotp_setsockopt(struct socket *sock, int level, int optname, From f5076c6ba02e8e24c61c40bbf48078929bc0fc79 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Mon, 22 Mar 2021 10:44:54 +0100 Subject: [PATCH 3/3] can: uapi: can.h: mark union inside struct can_frame packed In commit ea7800565a12 ("can: add optional DLC element to Classical CAN frame structure") the struct can_frame::can_dlc was put into an anonymous union with another u8 variable. For various reasons some members in struct can_frame and canfd_frame including the first 8 byes of data are expected to have the same memory layout. This is enforced by a BUILD_BUG_ON check in af_can.c. Since the above mentioned commit this check fails on ARM kernels compiled with the ARM OABI (which means CONFIG_AEABI not set). In this case -mabi=apcs-gnu is passed to the compiler, which leads to a structure size boundary of 32, instead of 8 compared to CONFIG_AEABI enabled. This means the the union in struct can_frame takes 4 bytes instead of the expected 1. Rong Chen illustrates the problem with pahole in the ARM OABI case: | struct can_frame { | canid_t can_id; /* 0 4 */ | union { | __u8 len; /* 4 1 */ | __u8 can_dlc; /* 4 1 */ | }; /* 4 4 */ | __u8 __pad; /* 8 1 */ | __u8 __res0; /* 9 1 */ | __u8 len8_dlc; /* 10 1 */ | | /* XXX 5 bytes hole, try to pack */ | | __u8 data[8] | __attribute__((__aligned__(8))); /* 16 8 */ | | /* size: 24, cachelines: 1, members: 6 */ | /* sum members: 19, holes: 1, sum holes: 5 */ | /* forced alignments: 1, forced holes: 1, sum forced holes: 5 */ | /* last cacheline: 24 bytes */ | } __attribute__((__aligned__(8))); Marking the anonymous union as __attribute__((packed)) fixes the BUILD_BUG_ON problem on these compilers. Fixes: ea7800565a12 ("can: add optional DLC element to Classical CAN frame structure") Reported-by: kernel test robot Suggested-by: Rong Chen Link: https://lore.kernel.org/linux-can/2c82ec23-3551-61b5-1bd8-178c3407ee83@hartkopp.net/ Link: https://lore.kernel.org/r/20210325125850.1620-3-socketcan@hartkopp.net Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- include/uapi/linux/can.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h index f75238ac6dce..c7535352fef6 100644 --- a/include/uapi/linux/can.h +++ b/include/uapi/linux/can.h @@ -113,7 +113,7 @@ struct can_frame { */ __u8 len; __u8 can_dlc; /* deprecated */ - }; + } __attribute__((packed)); /* disable padding added in some ABIs */ __u8 __pad; /* padding */ __u8 __res0; /* reserved / padding */ __u8 len8_dlc; /* optional DLC for 8 byte payload length (9 .. 15) */