RDMa/uverbs: Copy ex_hdr outside of SRCU read lock

The SRCU read lock protects the IB device pointer
and doesn't need to be called before copying user
provided header.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Leon Romanovsky 2018-02-21 18:12:40 +02:00 committed by Doug Ledford
parent 491d5c6a30
commit e21719fbbd
1 changed files with 6 additions and 7 deletions

View File

@ -709,8 +709,12 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
(command != IB_USER_VERBS_CMD_GET_CONTEXT || extended))
return -EINVAL;
if (extended && count < (sizeof(hdr) + sizeof(ex_hdr)))
return -EINVAL;
if (extended) {
if (count < (sizeof(hdr) + sizeof(ex_hdr)))
return -EINVAL;
if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
return -EFAULT;
}
srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
ib_dev = srcu_dereference(file->device->ib_dev,
@ -740,11 +744,6 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
struct ib_udata uhw;
size_t written_count = count;
if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr))) {
ret = -EFAULT;
goto out;
}
count -= sizeof(hdr) + sizeof(ex_hdr);
buf += sizeof(hdr) + sizeof(ex_hdr);