This is a note to let you know that I've just added the patch titled
IB/umad: Fix error handling
to the 3.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ib-umad-fix-error-handling.patch
and it can be found in the queue-3.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8ec0a0e6b58218bdc1db91dd70ebfcd6ad8dd6cd Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@xxxxxxx>
Date: Tue, 20 May 2014 10:33:41 +0200
Subject: IB/umad: Fix error handling
From: Bart Van Assche <bvanassche@xxxxxxx>
commit 8ec0a0e6b58218bdc1db91dd70ebfcd6ad8dd6cd upstream.
Avoid leaking a kref count in ib_umad_open() if port->ib_dev == NULL
or if nonseekable_open() fails.
Avoid leaking a kref count, that sm_sem is kept down and also that the
IB_PORT_SM capability mask is not cleared in ib_umad_sm_open() if
nonseekable_open() fails.
Since container_of() never returns NULL, remove the code that tests
whether container_of() returns NULL.
Moving the kref_get() call from the start of ib_umad_*open() to the
end is safe since it is the responsibility of the caller of these
functions to ensure that the cdev pointer remains valid until at least
when these functions return.
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
[ydroneaud@xxxxxxxxxx: rework a bit to reduce the amount of code changed]
Signed-off-by: Yann Droneaud <ydroneaud@xxxxxxxxxx>
[ nonseekable_open() can't actually fail, but.... - Roland ]
Signed-off-by: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/infiniband/core/user_mad.c | 49 ++++++++++++++++++++-----------------
1 file changed, 27 insertions(+), 22 deletions(-)
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -780,27 +780,19 @@ static int ib_umad_open(struct inode *in
{
struct ib_umad_port *port;
struct ib_umad_file *file;
- int ret;
+ int ret = -ENXIO;
port = container_of(inode->i_cdev, struct ib_umad_port, cdev);
- if (port)
- kref_get(&port->umad_dev->ref);
- else
- return -ENXIO;
mutex_lock(&port->file_mutex);
- if (!port->ib_dev) {
- ret = -ENXIO;
+ if (!port->ib_dev)
goto out;
- }
+ ret = -ENOMEM;
file = kzalloc(sizeof *file, GFP_KERNEL);
- if (!file) {
- kref_put(&port->umad_dev->ref, ib_umad_release_dev);
- ret = -ENOMEM;
+ if (!file)
goto out;
- }
mutex_init(&file->mutex);
spin_lock_init(&file->send_lock);
@@ -814,6 +806,13 @@ static int ib_umad_open(struct inode *in
list_add_tail(&file->port_list, &port->file_list);
ret = nonseekable_open(inode, filp);
+ if (ret) {
+ list_del(&file->port_list);
+ kfree(file);
+ goto out;
+ }
+
+ kref_get(&port->umad_dev->ref);
out:
mutex_unlock(&port->file_mutex);
@@ -880,10 +879,6 @@ static int ib_umad_sm_open(struct inode
int ret;
port = container_of(inode->i_cdev, struct ib_umad_port, sm_cdev);
- if (port)
- kref_get(&port->umad_dev->ref);
- else
- return -ENXIO;
if (filp->f_flags & O_NONBLOCK) {
if (down_trylock(&port->sm_sem)) {
@@ -898,17 +893,27 @@ static int ib_umad_sm_open(struct inode
}
ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
- if (ret) {
- up(&port->sm_sem);
- goto fail;
- }
+ if (ret)
+ goto err_up_sem;
filp->private_data = port;
- return nonseekable_open(inode, filp);
+ ret = nonseekable_open(inode, filp);
+ if (ret)
+ goto err_clr_sm_cap;
+
+ kref_get(&port->umad_dev->ref);
+
+ return 0;
+
+err_clr_sm_cap:
+ swap(props.set_port_cap_mask, props.clr_port_cap_mask);
+ ib_modify_port(port->ib_dev, port->port_num, 0, &props);
+
+err_up_sem:
+ up(&port->sm_sem);
fail:
- kref_put(&port->umad_dev->ref, ib_umad_release_dev);
return ret;
}
Patches currently in stable-queue which might be from bvanassche@xxxxxxx are
queue-3.15/ib-umad-fix-error-handling.patch
queue-3.15/ib-umad-fix-use-after-free-on-close.patch
queue-3.15/ib-srp-fix-a-sporadic-crash-triggered-by-cable-pulling.patch
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