From: Al Viro Date: Mon, 26 Jun 2017 20:47:01 +0000 (-0400) Subject: ipmi: get COMPAT_IPMICTL_RECEIVE_MSG in sync with the native one X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8b9e04f282c76786fad1a031b38e279bfababd9c;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git ipmi: get COMPAT_IPMICTL_RECEIVE_MSG in sync with the native one We want to know if copyout has succeeded before we commit to freeing msg. Signed-off-by: Al Viro --- diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c index f45119c5337d..7007beba918b 100644 --- a/drivers/char/ipmi/ipmi_devintf.c +++ b/drivers/char/ipmi/ipmi_devintf.c @@ -231,6 +231,102 @@ static int handle_send_req(ipmi_user_t user, return rv; } +static int handle_recv(struct ipmi_file_private *priv, + bool trunc, struct ipmi_recv *rsp, + int (*copyout)(struct ipmi_recv *, void __user *), + void __user *to) +{ + int addr_len; + struct list_head *entry; + struct ipmi_recv_msg *msg; + unsigned long flags; + int rv = 0; + + /* We claim a mutex because we don't want two + users getting something from the queue at a time. + Since we have to release the spinlock before we can + copy the data to the user, it's possible another + user will grab something from the queue, too. Then + the messages might get out of order if something + fails and the message gets put back onto the + queue. This mutex prevents that problem. */ + mutex_lock(&priv->recv_mutex); + + /* Grab the message off the list. */ + spin_lock_irqsave(&(priv->recv_msg_lock), flags); + if (list_empty(&(priv->recv_msgs))) { + spin_unlock_irqrestore(&(priv->recv_msg_lock), flags); + rv = -EAGAIN; + goto recv_err; + } + entry = priv->recv_msgs.next; + msg = list_entry(entry, struct ipmi_recv_msg, link); + list_del(entry); + spin_unlock_irqrestore(&(priv->recv_msg_lock), flags); + + addr_len = ipmi_addr_length(msg->addr.addr_type); + if (rsp->addr_len < addr_len) + { + rv = -EINVAL; + goto recv_putback_on_err; + } + + if (copy_to_user(rsp->addr, &(msg->addr), addr_len)) { + rv = -EFAULT; + goto recv_putback_on_err; + } + rsp->addr_len = addr_len; + + rsp->recv_type = msg->recv_type; + rsp->msgid = msg->msgid; + rsp->msg.netfn = msg->msg.netfn; + rsp->msg.cmd = msg->msg.cmd; + + if (msg->msg.data_len > 0) { + if (rsp->msg.data_len < msg->msg.data_len) { + rv = -EMSGSIZE; + if (trunc) + msg->msg.data_len = rsp->msg.data_len; + else + goto recv_putback_on_err; + } + + if (copy_to_user(rsp->msg.data, + msg->msg.data, + msg->msg.data_len)) + { + rv = -EFAULT; + goto recv_putback_on_err; + } + rsp->msg.data_len = msg->msg.data_len; + } else { + rsp->msg.data_len = 0; + } + + rv = copyout(rsp, to); + if (rv) + goto recv_putback_on_err; + + mutex_unlock(&priv->recv_mutex); + ipmi_free_recv_msg(msg); + return 0; + +recv_putback_on_err: + /* If we got an error, put the message back onto + the head of the queue. */ + spin_lock_irqsave(&(priv->recv_msg_lock), flags); + list_add(entry, &(priv->recv_msgs)); + spin_unlock_irqrestore(&(priv->recv_msg_lock), flags); +recv_err: + mutex_unlock(&priv->recv_mutex); + return rv; +} + +static int copyout_recv(struct ipmi_recv *rsp, void __user *to) +{ + return copy_to_user(to, rsp, sizeof(struct ipmi_recv)) ? -EFAULT : 0; +} + static int ipmi_ioctl(struct file *file, unsigned int cmd, unsigned long data) @@ -277,100 +373,12 @@ static int ipmi_ioctl(struct file *file, case IPMICTL_RECEIVE_MSG_TRUNC: { struct ipmi_recv rsp; - int addr_len; - struct list_head *entry; - struct ipmi_recv_msg *msg; - unsigned long flags; - - - rv = 0; - if (copy_from_user(&rsp, arg, sizeof(rsp))) { - rv = -EFAULT; - break; - } - - /* We claim a mutex because we don't want two - users getting something from the queue at a time. - Since we have to release the spinlock before we can - copy the data to the user, it's possible another - user will grab something from the queue, too. Then - the messages might get out of order if something - fails and the message gets put back onto the - queue. This mutex prevents that problem. */ - mutex_lock(&priv->recv_mutex); - - /* Grab the message off the list. */ - spin_lock_irqsave(&(priv->recv_msg_lock), flags); - if (list_empty(&(priv->recv_msgs))) { - spin_unlock_irqrestore(&(priv->recv_msg_lock), flags); - rv = -EAGAIN; - goto recv_err; - } - entry = priv->recv_msgs.next; - msg = list_entry(entry, struct ipmi_recv_msg, link); - list_del(entry); - spin_unlock_irqrestore(&(priv->recv_msg_lock), flags); - - addr_len = ipmi_addr_length(msg->addr.addr_type); - if (rsp.addr_len < addr_len) - { - rv = -EINVAL; - goto recv_putback_on_err; - } - - if (copy_to_user(rsp.addr, &(msg->addr), addr_len)) { - rv = -EFAULT; - goto recv_putback_on_err; - } - rsp.addr_len = addr_len; - - rsp.recv_type = msg->recv_type; - rsp.msgid = msg->msgid; - rsp.msg.netfn = msg->msg.netfn; - rsp.msg.cmd = msg->msg.cmd; - - if (msg->msg.data_len > 0) { - if (rsp.msg.data_len < msg->msg.data_len) { - rv = -EMSGSIZE; - if (cmd == IPMICTL_RECEIVE_MSG_TRUNC) { - msg->msg.data_len = rsp.msg.data_len; - } else { - goto recv_putback_on_err; - } - } - - if (copy_to_user(rsp.msg.data, - msg->msg.data, - msg->msg.data_len)) - { - rv = -EFAULT; - goto recv_putback_on_err; - } - rsp.msg.data_len = msg->msg.data_len; - } else { - rsp.msg.data_len = 0; - } - if (copy_to_user(arg, &rsp, sizeof(rsp))) { + if (copy_from_user(&rsp, arg, sizeof(rsp))) rv = -EFAULT; - goto recv_putback_on_err; - } - - mutex_unlock(&priv->recv_mutex); - ipmi_free_recv_msg(msg); - break; - - recv_putback_on_err: - /* If we got an error, put the message back onto - the head of the queue. */ - spin_lock_irqsave(&(priv->recv_msg_lock), flags); - list_add(entry, &(priv->recv_msgs)); - spin_unlock_irqrestore(&(priv->recv_msg_lock), flags); - mutex_unlock(&priv->recv_mutex); - break; - - recv_err: - mutex_unlock(&priv->recv_mutex); + else + rv = handle_recv(priv, cmd == IPMICTL_RECEIVE_MSG_TRUNC, + &rsp, copyout_recv, arg); break; } @@ -711,17 +719,6 @@ static long get_compat_ipmi_msg(struct ipmi_msg *p64, return 0; } -static long put_compat_ipmi_msg(struct ipmi_msg *p64, - struct compat_ipmi_msg __user *p32) -{ - if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) || - __put_user(p64->netfn, &p32->netfn) || - __put_user(p64->cmd, &p32->cmd) || - __put_user(p64->data_len, &p32->data_len)) - return -EFAULT; - return 0; -} - static long get_compat_ipmi_req(struct ipmi_req *p64, struct compat_ipmi_req __user *p32) { @@ -765,16 +762,19 @@ static long get_compat_ipmi_recv(struct ipmi_recv *p64, return 0; } -static long put_compat_ipmi_recv(struct ipmi_recv *p64, - struct compat_ipmi_recv __user *p32) +static int copyout_recv32(struct ipmi_recv *p64, void __user *to) { - if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) || - __put_user(p64->recv_type, &p32->recv_type) || - __put_user(p64->addr_len, &p32->addr_len) || - __put_user(p64->msgid, &p32->msgid) || - put_compat_ipmi_msg(&p64->msg, &p32->msg)) - return -EFAULT; - return 0; + struct compat_ipmi_recv v32; + memset(&v32, 0, sizeof(struct compat_ipmi_recv)); + v32.recv_type = p64->recv_type; + v32.addr = ptr_to_compat(p64->addr); + v32.addr_len = p64->addr_len; + v32.msgid = p64->msgid; + v32.msg.netfn = p64->msg.netfn; + v32.msg.cmd = p64->msg.cmd; + v32.msg.data_len = p64->msg.data_len; + v32.msg.data = ptr_to_compat(p64->msg.data); + return copy_to_user(to, &v32, sizeof(v32)) ? -EFAULT : 0; } /* @@ -783,7 +783,6 @@ static long put_compat_ipmi_recv(struct ipmi_recv *p64, static long compat_ipmi_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { - int rc; struct ipmi_file_private *priv = filep->private_data; switch(cmd) { @@ -811,32 +810,15 @@ static long compat_ipmi_ioctl(struct file *filep, unsigned int cmd, case COMPAT_IPMICTL_RECEIVE_MSG: case COMPAT_IPMICTL_RECEIVE_MSG_TRUNC: { - struct ipmi_recv __user *precv64; struct ipmi_recv recv64; memset(&recv64, 0, sizeof(recv64)); if (get_compat_ipmi_recv(&recv64, compat_ptr(arg))) return -EFAULT; - precv64 = compat_alloc_user_space(sizeof(recv64)); - if (copy_to_user(precv64, &recv64, sizeof(recv64))) - return -EFAULT; - - rc = ipmi_ioctl(filep, - ((cmd == COMPAT_IPMICTL_RECEIVE_MSG) - ? IPMICTL_RECEIVE_MSG - : IPMICTL_RECEIVE_MSG_TRUNC), - (unsigned long) precv64); - if (rc != 0) - return rc; - - if (copy_from_user(&recv64, precv64, sizeof(recv64))) - return -EFAULT; - - if (put_compat_ipmi_recv(&recv64, compat_ptr(arg))) - return -EFAULT; - - return rc; + return handle_recv(priv, + cmd == COMPAT_IPMICTL_RECEIVE_MSG_TRUNC, + &recv64, copyout_recv32, compat_ptr(arg)); } default: return ipmi_ioctl(filep, cmd, arg);