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RDMA/core: Fix locking in ib_uverbs_event_read

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commit 14e23bd6d22123f6f3b2747701fa6cd4c6d05873 upstream.

This should not be using ib_dev to test for disassociation, during
disassociation is_closed is set under lock and the waitq is triggered.

Instead check is_closed and be sure to re-obtain the lock to test the
value after the wait_event returns.

Fixes: 036b106357 ("IB/uverbs: Enable device removal when there are active user space applications")
Link: https://lore.kernel.org/r/1578504126-9400-12-git-send-email-yishaih@mellanox.com
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jason Gunthorpe 2020-01-08 19:22:03 +02:00 committed by Greg Kroah-Hartman
parent ab40fc36d6
commit 14d37518a9
1 changed files with 15 additions and 19 deletions
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34
drivers/infiniband/core/uverbs_main.c
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@ -273,7 +273,6 @@ void ib_uverbs_release_file(struct kref *ref)
} }
static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue, static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
struct ib_uverbs_file *uverbs_file,
struct file *filp, char __user *buf, struct file *filp, char __user *buf,
size_t count, loff_t *pos, size_t count, loff_t *pos,
size_t eventsz) size_t eventsz)
@ -291,19 +290,16 @@ static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
if (wait_event_interruptible(ev_queue->poll_wait, if (wait_event_interruptible(ev_queue->poll_wait,
(!list_empty(&ev_queue->event_list) || (!list_empty(&ev_queue->event_list) ||
/* The barriers built into wait_event_interruptible() ev_queue->is_closed)))
* and wake_up() guarentee this will see the null set
* without using RCU
*/
!uverbs_file->device->ib_dev)))
return -ERESTARTSYS; return -ERESTARTSYS;
/* If device was disassociated and no event exists set an error */
if (list_empty(&ev_queue->event_list) &&
!uverbs_file->device->ib_dev)
return -EIO;
spin_lock_irq(&ev_queue->lock); spin_lock_irq(&ev_queue->lock);
/* If device was disassociated and no event exists set an error */
if (list_empty(&ev_queue->event_list) && ev_queue->is_closed) {
spin_unlock_irq(&ev_queue->lock);
return -EIO;
}
} }
event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list); event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
@ -338,8 +334,7 @@ static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
{ {
struct ib_uverbs_async_event_file *file = filp->private_data; struct ib_uverbs_async_event_file *file = filp->private_data;
return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp, return ib_uverbs_event_read(&file->ev_queue, filp, buf, count, pos,
buf, count, pos,
sizeof(struct ib_uverbs_async_event_desc)); sizeof(struct ib_uverbs_async_event_desc));
} }
@ -349,9 +344,8 @@ static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
struct ib_uverbs_completion_event_file *comp_ev_file = struct ib_uverbs_completion_event_file *comp_ev_file =
filp->private_data; filp->private_data;
return ib_uverbs_event_read(&comp_ev_file->ev_queue, return ib_uverbs_event_read(&comp_ev_file->ev_queue, filp, buf, count,
comp_ev_file->uobj.ufile, filp, pos,
buf, count, pos,
sizeof(struct ib_uverbs_comp_event_desc)); sizeof(struct ib_uverbs_comp_event_desc));
} }
@ -374,7 +368,9 @@ static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
static __poll_t ib_uverbs_async_event_poll(struct file *filp, static __poll_t ib_uverbs_async_event_poll(struct file *filp,
struct poll_table_struct *wait) struct poll_table_struct *wait)
{ {
return ib_uverbs_event_poll(filp->private_data, filp, wait); struct ib_uverbs_async_event_file *file = filp->private_data;
return ib_uverbs_event_poll(&file->ev_queue, filp, wait);
} }
static __poll_t ib_uverbs_comp_event_poll(struct file *filp, static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
@ -388,9 +384,9 @@ static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on) static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
{ {
struct ib_uverbs_event_queue *ev_queue = filp->private_data; struct ib_uverbs_async_event_file *file = filp->private_data;
return fasync_helper(fd, filp, on, &ev_queue->async_queue); return fasync_helper(fd, filp, on, &file->ev_queue.async_queue);
} }
static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on) static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)