Backport uio fixes to 4.14, to fix use-after-free memory errors.
Changed __poll_t to unsigned int as the former not found in 4.14, and
resolved some patch context conflicts.
Hailong Liu (1):
uio: fix wrong return value from uio_mmap()
Hamish Martin (2):
uio: Reduce return paths from uio_write()
uio: Prevent device destruction while fds are open
Xiubo Li (5):
uio: use request_threaded_irq instead
uio: change to use the mutex lock instead of the spin lock
uio: fix crash after the device is unregistered
uio: fix possible circular locking dependency
Revert "uio: use request_threaded_irq instead"
drivers/uio/uio.c | 206 ++++++++++++++++++++++++++++---------
include/linux/uio_driver.h | 4 +-
2 files changed, 163 insertions(+), 47 deletions(-)
--
2.20.1
From: Xiubo Li <[email protected]>
commit 9421e45f5ff3d558cf8b75a8cc0824530caf3453 upstream.
Prepraing for changing to use mutex lock.
Signed-off-by: Xiubo Li <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 288c4b977184..c97945a3f572 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -911,8 +911,9 @@ int __uio_register_device(struct module *owner,
* FDs at the time of unregister and therefore may not be
* freed until they are released.
*/
- ret = request_irq(info->irq, uio_interrupt,
- info->irq_flags, info->name, idev);
+ ret = request_threaded_irq(info->irq, NULL, uio_interrupt,
+ info->irq_flags, info->name, idev);
+
if (ret) {
info->uio_dev = NULL;
goto err_request_irq;
--
2.20.1
From: Hailong Liu <[email protected]>
commit e7de2590f18a272e63732b9d519250d1b522b2c4 upstream.
uio_mmap has multiple fail paths to set return value to nonzero then
goto out. However, it always returns *0* from the *out* at end, and
this will mislead callers who check the return value of this function.
Fixes: 57c5f4df0a5a0ee ("uio: fix crash after the device is unregistered")
CC: Xiubo Li <[email protected]>
Signed-off-by: Hailong Liu <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Jiang Biao <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 262610192755..fed2d8fa4d4d 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -816,7 +816,7 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
out:
mutex_unlock(&idev->info_lock);
- return 0;
+ return ret;
}
static const struct file_operations uio_fops = {
--
2.20.1
From: Xiubo Li <[email protected]>
commit 3d27c4de8d4fb2d4099ff324671792aa2578c6f9 upstream.
Since mutex lock in irq hanler is useless currently, here will
remove it together with it.
This reverts commit 9421e45f5ff3d558cf8b75a8cc0824530caf3453.
Reported-by: [email protected]
CC: Ahsan Atta <[email protected]>
Signed-off-by: Xiubo Li <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 4e0cb7cdf739..fb5c9701b1fb 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -445,13 +445,10 @@ static irqreturn_t uio_interrupt(int irq, void *dev_id)
struct uio_device *idev = (struct uio_device *)dev_id;
irqreturn_t ret;
- mutex_lock(&idev->info_lock);
-
ret = idev->info->handler(irq, idev->info);
if (ret == IRQ_HANDLED)
uio_event_notify(idev->info);
- mutex_unlock(&idev->info_lock);
return ret;
}
@@ -974,9 +971,8 @@ int __uio_register_device(struct module *owner,
* FDs at the time of unregister and therefore may not be
* freed until they are released.
*/
- ret = request_threaded_irq(info->irq, NULL, uio_interrupt,
- info->irq_flags, info->name, idev);
-
+ ret = request_irq(info->irq, uio_interrupt,
+ info->irq_flags, info->name, idev);
if (ret) {
info->uio_dev = NULL;
goto err_request_irq;
--
2.20.1
From: Xiubo Li <[email protected]>
commit b34e9a15b37b8ddbf06a4da142b0c39c74211eb4 upstream.
The call trace:
XXX/1910 is trying to acquire lock:
(&mm->mmap_sem){++++++}, at: [<ffffffff97008c87>] might_fault+0x57/0xb0
but task is already holding lock:
(&idev->info_lock){+.+...}, at: [<ffffffffc0638a06>] uio_write+0x46/0x130 [uio]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&idev->info_lock){+.+...}:
[<ffffffff96f31fc9>] lock_acquire+0x99/0x1e0
[<ffffffff975edad3>] mutex_lock_nested+0x93/0x410
[<ffffffffc063873d>] uio_mmap+0x2d/0x170 [uio]
[<ffffffff97016b58>] mmap_region+0x428/0x650
[<ffffffff97017138>] do_mmap+0x3b8/0x4e0
[<ffffffff96ffaba3>] vm_mmap_pgoff+0xd3/0x120
[<ffffffff97015261>] SyS_mmap_pgoff+0x1f1/0x270
[<ffffffff96e387c2>] SyS_mmap+0x22/0x30
[<ffffffff975ff315>] system_call_fastpath+0x1c/0x21
-> #0 (&mm->mmap_sem){++++++}:
[<ffffffff96f30e9c>] __lock_acquire+0xdac/0x15f0
[<ffffffff96f31fc9>] lock_acquire+0x99/0x1e0
[<ffffffff97008cb4>] might_fault+0x84/0xb0
[<ffffffffc0638a74>] uio_write+0xb4/0x130 [uio]
[<ffffffff9706ffa3>] vfs_write+0xc3/0x1f0
[<ffffffff97070e2a>] SyS_write+0x8a/0x100
[<ffffffff975ff315>] system_call_fastpath+0x1c/0x21
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&idev->info_lock);
lock(&mm->mmap_sem);
lock(&idev->info_lock);
lock(&mm->mmap_sem);
*** DEADLOCK ***
1 lock held by XXX/1910:
#0: (&idev->info_lock){+.+...}, at: [<ffffffffc0638a06>] uio_write+0x46/0x130 [uio]
stack backtrace:
CPU: 0 PID: 1910 Comm: XXX Kdump: loaded Not tainted #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
Call Trace:
[<ffffffff975e9211>] dump_stack+0x19/0x1b
[<ffffffff975e260a>] print_circular_bug+0x1f9/0x207
[<ffffffff96f2f6a7>] check_prevs_add+0x957/0x960
[<ffffffff96f30e9c>] __lock_acquire+0xdac/0x15f0
[<ffffffff96f2fb19>] ? mark_held_locks+0xb9/0x140
[<ffffffff96f31fc9>] lock_acquire+0x99/0x1e0
[<ffffffff97008c87>] ? might_fault+0x57/0xb0
[<ffffffff97008cb4>] might_fault+0x84/0xb0
[<ffffffff97008c87>] ? might_fault+0x57/0xb0
[<ffffffffc0638a74>] uio_write+0xb4/0x130 [uio]
[<ffffffff9706ffa3>] vfs_write+0xc3/0x1f0
[<ffffffff9709349c>] ? fget_light+0xfc/0x510
[<ffffffff97070e2a>] SyS_write+0x8a/0x100
[<ffffffff975ff315>] system_call_fastpath+0x1c/0x21
Signed-off-by: Xiubo Li <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index fed2d8fa4d4d..4e0cb7cdf739 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -627,6 +627,12 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
ssize_t retval;
s32 irq_on;
+ if (count != sizeof(s32))
+ return -EINVAL;
+
+ if (copy_from_user(&irq_on, buf, count))
+ return -EFAULT;
+
mutex_lock(&idev->info_lock);
if (!idev->info) {
retval = -EINVAL;
@@ -638,21 +644,11 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
goto out;
}
- if (count != sizeof(s32)) {
- retval = -EINVAL;
- goto out;
- }
-
if (!idev->info->irqcontrol) {
retval = -ENOSYS;
goto out;
}
- if (copy_from_user(&irq_on, buf, count)) {
- retval = -EFAULT;
- goto out;
- }
-
retval = idev->info->irqcontrol(idev->info, irq_on);
out:
--
2.20.1
From: Xiubo Li <[email protected]>
commit 543af5861f41af0a5d2432f6fb5976af50f9cee5 upstream.
We are hitting a regression with the following commit:
commit a93e7b331568227500186a465fee3c2cb5dffd1f
Author: Hamish Martin <[email protected]>
Date: Mon May 14 13:32:23 2018 +1200
uio: Prevent device destruction while fds are open
The problem is the addition of spin_lock_irqsave in uio_write. This
leads to hitting uio_write -> copy_from_user -> _copy_from_user ->
might_fault and the logs filling up with sleeping warnings.
I also noticed some uio drivers allocate memory, sleep, grab mutexes
from callouts like open() and release and uio is now doing
spin_lock_irqsave while calling them.
Reported-by: Mike Christie <[email protected]>
CC: Hamish Martin <[email protected]>
Reviewed-by: Hamish Martin <[email protected]>
Signed-off-by: Xiubo Li <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 32 +++++++++++++-------------------
include/linux/uio_driver.h | 2 +-
2 files changed, 14 insertions(+), 20 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index c97945a3f572..4441235a56cc 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -435,7 +435,6 @@ static int uio_open(struct inode *inode, struct file *filep)
struct uio_device *idev;
struct uio_listener *listener;
int ret = 0;
- unsigned long flags;
mutex_lock(&minor_lock);
idev = idr_find(&uio_idr, iminor(inode));
@@ -462,10 +461,10 @@ static int uio_open(struct inode *inode, struct file *filep)
listener->event_count = atomic_read(&idev->event);
filep->private_data = listener;
- spin_lock_irqsave(&idev->info_lock, flags);
+ mutex_lock(&idev->info_lock);
if (idev->info && idev->info->open)
ret = idev->info->open(idev->info, inode);
- spin_unlock_irqrestore(&idev->info_lock, flags);
+ mutex_unlock(&idev->info_lock);
if (ret)
goto err_infoopen;
@@ -497,12 +496,11 @@ static int uio_release(struct inode *inode, struct file *filep)
int ret = 0;
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
- unsigned long flags;
- spin_lock_irqsave(&idev->info_lock, flags);
+ mutex_lock(&idev->info_lock);
if (idev->info && idev->info->release)
ret = idev->info->release(idev->info, inode);
- spin_unlock_irqrestore(&idev->info_lock, flags);
+ mutex_unlock(&idev->info_lock);
module_put(idev->owner);
kfree(listener);
@@ -515,12 +513,11 @@ static unsigned int uio_poll(struct file *filep, poll_table *wait)
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
unsigned int ret = 0;
- unsigned long flags;
- spin_lock_irqsave(&idev->info_lock, flags);
+ mutex_lock(&idev->info_lock);
if (!idev->info || !idev->info->irq)
ret = -EIO;
- spin_unlock_irqrestore(&idev->info_lock, flags);
+ mutex_unlock(&idev->info_lock);
if (ret)
return ret;
@@ -539,12 +536,11 @@ static ssize_t uio_read(struct file *filep, char __user *buf,
DECLARE_WAITQUEUE(wait, current);
ssize_t retval = 0;
s32 event_count;
- unsigned long flags;
- spin_lock_irqsave(&idev->info_lock, flags);
+ mutex_lock(&idev->info_lock);
if (!idev->info || !idev->info->irq)
retval = -EIO;
- spin_unlock_irqrestore(&idev->info_lock, flags);
+ mutex_unlock(&idev->info_lock);
if (retval)
return retval;
@@ -594,9 +590,8 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
struct uio_device *idev = listener->dev;
ssize_t retval;
s32 irq_on;
- unsigned long flags;
- spin_lock_irqsave(&idev->info_lock, flags);
+ mutex_lock(&idev->info_lock);
if (!idev->info || !idev->info->irq) {
retval = -EIO;
goto out;
@@ -620,7 +615,7 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
retval = idev->info->irqcontrol(idev->info, irq_on);
out:
- spin_unlock_irqrestore(&idev->info_lock, flags);
+ mutex_unlock(&idev->info_lock);
return retval ? retval : sizeof(s32);
}
@@ -874,7 +869,7 @@ int __uio_register_device(struct module *owner,
idev->owner = owner;
idev->info = info;
- spin_lock_init(&idev->info_lock);
+ mutex_init(&idev->info_lock);
init_waitqueue_head(&idev->wait);
atomic_set(&idev->event, 0);
@@ -940,7 +935,6 @@ EXPORT_SYMBOL_GPL(__uio_register_device);
void uio_unregister_device(struct uio_info *info)
{
struct uio_device *idev;
- unsigned long flags;
if (!info || !info->uio_dev)
return;
@@ -954,9 +948,9 @@ void uio_unregister_device(struct uio_info *info)
if (info->irq && info->irq != UIO_IRQ_CUSTOM)
free_irq(info->irq, idev);
- spin_lock_irqsave(&idev->info_lock, flags);
+ mutex_lock(&idev->info_lock);
idev->info = NULL;
- spin_unlock_irqrestore(&idev->info_lock, flags);
+ mutex_unlock(&idev->info_lock);
device_unregister(&idev->dev);
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 6c5f2074e14f..6f8b68cd460f 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -75,7 +75,7 @@ struct uio_device {
struct fasync_struct *async_queue;
wait_queue_head_t wait;
struct uio_info *info;
- spinlock_t info_lock;
+ struct mutex info_lock;
struct kobject *map_dir;
struct kobject *portio_dir;
};
--
2.20.1
From: Hamish Martin <[email protected]>
commit 81daa406c2cc97d85eef9409400404efc2a3f756 upstream.
Drive all return paths for uio_write() through a single block at the
end of the function.
Signed-off-by: Hamish Martin <[email protected]>
Reviewed-by: Chris Packham <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 654579bc1e54..10f249628e79 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -570,20 +570,29 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
ssize_t retval;
s32 irq_on;
- if (!idev->info->irq)
- return -EIO;
+ if (!idev->info->irq) {
+ retval = -EIO;
+ goto out;
+ }
- if (count != sizeof(s32))
- return -EINVAL;
+ if (count != sizeof(s32)) {
+ retval = -EINVAL;
+ goto out;
+ }
- if (!idev->info->irqcontrol)
- return -ENOSYS;
+ if (!idev->info->irqcontrol) {
+ retval = -ENOSYS;
+ goto out;
+ }
- if (copy_from_user(&irq_on, buf, count))
- return -EFAULT;
+ if (copy_from_user(&irq_on, buf, count)) {
+ retval = -EFAULT;
+ goto out;
+ }
retval = idev->info->irqcontrol(idev->info, irq_on);
+out:
return retval ? retval : sizeof(s32);
}
--
2.20.1
From: Hamish Martin <[email protected]>
commit a93e7b331568227500186a465fee3c2cb5dffd1f upstream.
Prevent destruction of a uio_device while user space apps hold open
file descriptors to that device. Further, access to the 'info' member
of the struct uio_device is protected by spinlock. This is to ensure
stale pointers to data not under control of the UIO subsystem are not
dereferenced.
Signed-off-by: Hamish Martin <[email protected]>
Reviewed-by: Chris Packham <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
[4.14 change __poll_t to unsigned int]
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 98 ++++++++++++++++++++++++++++----------
include/linux/uio_driver.h | 4 +-
2 files changed, 75 insertions(+), 27 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 10f249628e79..288c4b977184 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -272,7 +272,7 @@ static int uio_dev_add_attributes(struct uio_device *idev)
if (!map_found) {
map_found = 1;
idev->map_dir = kobject_create_and_add("maps",
- &idev->dev->kobj);
+ &idev->dev.kobj);
if (!idev->map_dir) {
ret = -ENOMEM;
goto err_map;
@@ -301,7 +301,7 @@ static int uio_dev_add_attributes(struct uio_device *idev)
if (!portio_found) {
portio_found = 1;
idev->portio_dir = kobject_create_and_add("portio",
- &idev->dev->kobj);
+ &idev->dev.kobj);
if (!idev->portio_dir) {
ret = -ENOMEM;
goto err_portio;
@@ -344,7 +344,7 @@ static int uio_dev_add_attributes(struct uio_device *idev)
kobject_put(&map->kobj);
}
kobject_put(idev->map_dir);
- dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
+ dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret);
return ret;
}
@@ -381,7 +381,7 @@ static int uio_get_minor(struct uio_device *idev)
idev->minor = retval;
retval = 0;
} else if (retval == -ENOSPC) {
- dev_err(idev->dev, "too many uio devices\n");
+ dev_err(&idev->dev, "too many uio devices\n");
retval = -EINVAL;
}
mutex_unlock(&minor_lock);
@@ -435,6 +435,7 @@ static int uio_open(struct inode *inode, struct file *filep)
struct uio_device *idev;
struct uio_listener *listener;
int ret = 0;
+ unsigned long flags;
mutex_lock(&minor_lock);
idev = idr_find(&uio_idr, iminor(inode));
@@ -444,9 +445,11 @@ static int uio_open(struct inode *inode, struct file *filep)
goto out;
}
+ get_device(&idev->dev);
+
if (!try_module_get(idev->owner)) {
ret = -ENODEV;
- goto out;
+ goto err_module_get;
}
listener = kmalloc(sizeof(*listener), GFP_KERNEL);
@@ -459,11 +462,13 @@ static int uio_open(struct inode *inode, struct file *filep)
listener->event_count = atomic_read(&idev->event);
filep->private_data = listener;
- if (idev->info->open) {
+ spin_lock_irqsave(&idev->info_lock, flags);
+ if (idev->info && idev->info->open)
ret = idev->info->open(idev->info, inode);
- if (ret)
- goto err_infoopen;
- }
+ spin_unlock_irqrestore(&idev->info_lock, flags);
+ if (ret)
+ goto err_infoopen;
+
return 0;
err_infoopen:
@@ -472,6 +477,9 @@ static int uio_open(struct inode *inode, struct file *filep)
err_alloc_listener:
module_put(idev->owner);
+err_module_get:
+ put_device(&idev->dev);
+
out:
return ret;
}
@@ -489,12 +497,16 @@ static int uio_release(struct inode *inode, struct file *filep)
int ret = 0;
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
+ unsigned long flags;
- if (idev->info->release)
+ spin_lock_irqsave(&idev->info_lock, flags);
+ if (idev->info && idev->info->release)
ret = idev->info->release(idev->info, inode);
+ spin_unlock_irqrestore(&idev->info_lock, flags);
module_put(idev->owner);
kfree(listener);
+ put_device(&idev->dev);
return ret;
}
@@ -502,9 +514,16 @@ static unsigned int uio_poll(struct file *filep, poll_table *wait)
{
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
+ unsigned int ret = 0;
+ unsigned long flags;
- if (!idev->info->irq)
- return -EIO;
+ spin_lock_irqsave(&idev->info_lock, flags);
+ if (!idev->info || !idev->info->irq)
+ ret = -EIO;
+ spin_unlock_irqrestore(&idev->info_lock, flags);
+
+ if (ret)
+ return ret;
poll_wait(filep, &idev->wait, wait);
if (listener->event_count != atomic_read(&idev->event))
@@ -518,11 +537,17 @@ static ssize_t uio_read(struct file *filep, char __user *buf,
struct uio_listener *listener = filep->private_data;
struct uio_device *idev = listener->dev;
DECLARE_WAITQUEUE(wait, current);
- ssize_t retval;
+ ssize_t retval = 0;
s32 event_count;
+ unsigned long flags;
- if (!idev->info->irq)
- return -EIO;
+ spin_lock_irqsave(&idev->info_lock, flags);
+ if (!idev->info || !idev->info->irq)
+ retval = -EIO;
+ spin_unlock_irqrestore(&idev->info_lock, flags);
+
+ if (retval)
+ return retval;
if (count != sizeof(s32))
return -EINVAL;
@@ -569,8 +594,10 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
struct uio_device *idev = listener->dev;
ssize_t retval;
s32 irq_on;
+ unsigned long flags;
- if (!idev->info->irq) {
+ spin_lock_irqsave(&idev->info_lock, flags);
+ if (!idev->info || !idev->info->irq) {
retval = -EIO;
goto out;
}
@@ -593,6 +620,7 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
retval = idev->info->irqcontrol(idev->info, irq_on);
out:
+ spin_unlock_irqrestore(&idev->info_lock, flags);
return retval ? retval : sizeof(s32);
}
@@ -809,6 +837,13 @@ static void release_uio_class(void)
uio_major_cleanup();
}
+static void uio_device_release(struct device *dev)
+{
+ struct uio_device *idev = dev_get_drvdata(dev);
+
+ kfree(idev);
+}
+
/**
* uio_register_device - register a new userspace IO device
* @owner: module that creates the new device
@@ -832,13 +867,14 @@ int __uio_register_device(struct module *owner,
info->uio_dev = NULL;
- idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
+ idev = kzalloc(sizeof(*idev), GFP_KERNEL);
if (!idev) {
return -ENOMEM;
}
idev->owner = owner;
idev->info = info;
+ spin_lock_init(&idev->info_lock);
init_waitqueue_head(&idev->wait);
atomic_set(&idev->event, 0);
@@ -846,14 +882,19 @@ int __uio_register_device(struct module *owner,
if (ret)
return ret;
- idev->dev = device_create(&uio_class, parent,
- MKDEV(uio_major, idev->minor), idev,
- "uio%d", idev->minor);
- if (IS_ERR(idev->dev)) {
- printk(KERN_ERR "UIO: device register failed\n");
- ret = PTR_ERR(idev->dev);
+ idev->dev.devt = MKDEV(uio_major, idev->minor);
+ idev->dev.class = &uio_class;
+ idev->dev.parent = parent;
+ idev->dev.release = uio_device_release;
+ dev_set_drvdata(&idev->dev, idev);
+
+ ret = dev_set_name(&idev->dev, "uio%d", idev->minor);
+ if (ret)
+ goto err_device_create;
+
+ ret = device_register(&idev->dev);
+ if (ret)
goto err_device_create;
- }
ret = uio_dev_add_attributes(idev);
if (ret)
@@ -883,7 +924,7 @@ int __uio_register_device(struct module *owner,
err_request_irq:
uio_dev_del_attributes(idev);
err_uio_dev_add_attributes:
- device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
+ device_unregister(&idev->dev);
err_device_create:
uio_free_minor(idev);
return ret;
@@ -898,6 +939,7 @@ EXPORT_SYMBOL_GPL(__uio_register_device);
void uio_unregister_device(struct uio_info *info)
{
struct uio_device *idev;
+ unsigned long flags;
if (!info || !info->uio_dev)
return;
@@ -911,7 +953,11 @@ void uio_unregister_device(struct uio_info *info)
if (info->irq && info->irq != UIO_IRQ_CUSTOM)
free_irq(info->irq, idev);
- device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
+ spin_lock_irqsave(&idev->info_lock, flags);
+ idev->info = NULL;
+ spin_unlock_irqrestore(&idev->info_lock, flags);
+
+ device_unregister(&idev->dev);
return;
}
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 3c85c81b0027..6c5f2074e14f 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -14,6 +14,7 @@
#ifndef _UIO_DRIVER_H_
#define _UIO_DRIVER_H_
+#include <linux/device.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
@@ -68,12 +69,13 @@ struct uio_port {
struct uio_device {
struct module *owner;
- struct device *dev;
+ struct device dev;
int minor;
atomic_t event;
struct fasync_struct *async_queue;
wait_queue_head_t wait;
struct uio_info *info;
+ spinlock_t info_lock;
struct kobject *map_dir;
struct kobject *portio_dir;
};
--
2.20.1
From: Xiubo Li <[email protected]>
commit 57c5f4df0a5a0ee83df799991251e2ee93a5e4e9 upstream.
For the target_core_user use case, after the device is unregistered
it maybe still opened in user space, then the kernel will crash, like:
[ 251.163692] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 251.163820] IP: [<ffffffffc0736213>] show_name+0x23/0x40 [uio]
[ 251.163965] PGD 8000000062694067 PUD 62696067 PMD 0
[ 251.164097] Oops: 0000 [#1] SMP
...
[ 251.165605] e1000 mptscsih mptbase drm_panel_orientation_quirks dm_mirror dm_region_hash dm_log dm_mod
[ 251.166014] CPU: 0 PID: 13380 Comm: tcmu-runner Kdump: loaded Not tainted 3.10.0-916.el7.test.x86_64 #1
[ 251.166381] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
[ 251.166747] task: ffff971eb91db0c0 ti: ffff971e9e384000 task.ti: ffff971e9e384000
[ 251.167137] RIP: 0010:[<ffffffffc0736213>] [<ffffffffc0736213>] show_name+0x23/0x40 [uio]
[ 251.167563] RSP: 0018:ffff971e9e387dc8 EFLAGS: 00010282
[ 251.167978] RAX: 0000000000000000 RBX: ffff971e9e3f8000 RCX: ffff971eb8368d98
[ 251.168408] RDX: ffff971e9e3f8000 RSI: ffffffffc0738084 RDI: ffff971e9e3f8000
[ 251.168856] RBP: ffff971e9e387dd0 R08: ffff971eb8bc0018 R09: 0000000000000000
[ 251.169296] R10: 0000000000001000 R11: ffffffffa09d444d R12: ffffffffa1076e80
[ 251.169750] R13: ffff971e9e387f18 R14: 0000000000000001 R15: ffff971e9cfb1c80
[ 251.170213] FS: 00007ff37d175880(0000) GS:ffff971ebb600000(0000) knlGS:0000000000000000
[ 251.170693] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 251.171248] CR2: 0000000000000008 CR3: 00000000001f6000 CR4: 00000000003607f0
[ 251.172071] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 251.172640] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 251.173236] Call Trace:
[ 251.173789] [<ffffffffa0c9b2d3>] dev_attr_show+0x23/0x60
[ 251.174356] [<ffffffffa0f561b2>] ? mutex_lock+0x12/0x2f
[ 251.174892] [<ffffffffa0ac6d9f>] sysfs_kf_seq_show+0xcf/0x1f0
[ 251.175433] [<ffffffffa0ac54e6>] kernfs_seq_show+0x26/0x30
[ 251.175981] [<ffffffffa0a63be0>] seq_read+0x110/0x3f0
[ 251.176609] [<ffffffffa0ac5d45>] kernfs_fop_read+0xf5/0x160
[ 251.177158] [<ffffffffa0a3d3af>] vfs_read+0x9f/0x170
[ 251.177707] [<ffffffffa0a3e27f>] SyS_read+0x7f/0xf0
[ 251.178268] [<ffffffffa0f648af>] system_call_fastpath+0x1c/0x21
[ 251.178823] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 d3 e8 7e 96 56 e0 48 8b 80 d8 02 00 00 48 89 df 48 c7 c6 84 80 73 c0 <48> 8b 50 08 31 c0 e8 e2 67 44 e0 5b 48 98 5d c3 0f 1f 00 66 2e
[ 251.180115] RIP [<ffffffffc0736213>] show_name+0x23/0x40 [uio]
[ 251.180820] RSP <ffff971e9e387dc8>
[ 251.181473] CR2: 0000000000000008
CC: Hamish Martin <[email protected]>
CC: Mike Christie <[email protected]>
Reviewed-by: Hamish Martin <[email protected]>
Signed-off-by: Xiubo Li <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
---
drivers/uio/uio.c | 104 +++++++++++++++++++++++++++++++++++++++-------
1 file changed, 88 insertions(+), 16 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 4441235a56cc..262610192755 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -215,7 +215,20 @@ static ssize_t name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct uio_device *idev = dev_get_drvdata(dev);
- return sprintf(buf, "%s\n", idev->info->name);
+ int ret;
+
+ mutex_lock(&idev->info_lock);
+ if (!idev->info) {
+ ret = -EINVAL;
+ dev_err(dev, "the device has been unregistered\n");
+ goto out;
+ }
+
+ ret = sprintf(buf, "%s\n", idev->info->name);
+
+out:
+ mutex_unlock(&idev->info_lock);
+ return ret;
}
static DEVICE_ATTR_RO(name);
@@ -223,7 +236,20 @@ static ssize_t version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct uio_device *idev = dev_get_drvdata(dev);
- return sprintf(buf, "%s\n", idev->info->version);
+ int ret;
+
+ mutex_lock(&idev->info_lock);
+ if (!idev->info) {
+ ret = -EINVAL;
+ dev_err(dev, "the device has been unregistered\n");
+ goto out;
+ }
+
+ ret = sprintf(buf, "%s\n", idev->info->version);
+
+out:
+ mutex_unlock(&idev->info_lock);
+ return ret;
}
static DEVICE_ATTR_RO(version);
@@ -417,11 +443,15 @@ EXPORT_SYMBOL_GPL(uio_event_notify);
static irqreturn_t uio_interrupt(int irq, void *dev_id)
{
struct uio_device *idev = (struct uio_device *)dev_id;
- irqreturn_t ret = idev->info->handler(irq, idev->info);
+ irqreturn_t ret;
+
+ mutex_lock(&idev->info_lock);
+ ret = idev->info->handler(irq, idev->info);
if (ret == IRQ_HANDLED)
uio_event_notify(idev->info);
+ mutex_unlock(&idev->info_lock);
return ret;
}
@@ -462,6 +492,12 @@ static int uio_open(struct inode *inode, struct file *filep)
filep->private_data = listener;
mutex_lock(&idev->info_lock);
+ if (!idev->info) {
+ mutex_unlock(&idev->info_lock);
+ ret = -EINVAL;
+ goto err_alloc_listener;
+ }
+
if (idev->info && idev->info->open)
ret = idev->info->open(idev->info, inode);
mutex_unlock(&idev->info_lock);
@@ -592,6 +628,11 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
s32 irq_on;
mutex_lock(&idev->info_lock);
+ if (!idev->info) {
+ retval = -EINVAL;
+ goto out;
+ }
+
if (!idev->info || !idev->info->irq) {
retval = -EIO;
goto out;
@@ -637,10 +678,20 @@ static int uio_vma_fault(struct vm_fault *vmf)
struct page *page;
unsigned long offset;
void *addr;
+ int ret = 0;
+ int mi;
- int mi = uio_find_mem_index(vmf->vma);
- if (mi < 0)
- return VM_FAULT_SIGBUS;
+ mutex_lock(&idev->info_lock);
+ if (!idev->info) {
+ ret = VM_FAULT_SIGBUS;
+ goto out;
+ }
+
+ mi = uio_find_mem_index(vmf->vma);
+ if (mi < 0) {
+ ret = VM_FAULT_SIGBUS;
+ goto out;
+ }
/*
* We need to subtract mi because userspace uses offset = N*PAGE_SIZE
@@ -655,7 +706,11 @@ static int uio_vma_fault(struct vm_fault *vmf)
page = vmalloc_to_page(addr);
get_page(page);
vmf->page = page;
- return 0;
+
+out:
+ mutex_unlock(&idev->info_lock);
+
+ return ret;
}
static const struct vm_operations_struct uio_logical_vm_ops = {
@@ -680,6 +735,7 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
struct uio_device *idev = vma->vm_private_data;
int mi = uio_find_mem_index(vma);
struct uio_mem *mem;
+
if (mi < 0)
return -EINVAL;
mem = idev->info->mem + mi;
@@ -721,30 +777,46 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
vma->vm_private_data = idev;
+ mutex_lock(&idev->info_lock);
+ if (!idev->info) {
+ ret = -EINVAL;
+ goto out;
+ }
+
mi = uio_find_mem_index(vma);
- if (mi < 0)
- return -EINVAL;
+ if (mi < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
requested_pages = vma_pages(vma);
actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
+ idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
- if (requested_pages > actual_pages)
- return -EINVAL;
+ if (requested_pages > actual_pages) {
+ ret = -EINVAL;
+ goto out;
+ }
if (idev->info->mmap) {
ret = idev->info->mmap(idev->info, vma);
- return ret;
+ goto out;
}
switch (idev->info->mem[mi].memtype) {
case UIO_MEM_PHYS:
- return uio_mmap_physical(vma);
+ ret = uio_mmap_physical(vma);
+ break;
case UIO_MEM_LOGICAL:
case UIO_MEM_VIRTUAL:
- return uio_mmap_logical(vma);
+ ret = uio_mmap_logical(vma);
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
}
+
+out:
+ mutex_unlock(&idev->info_lock);
+ return 0;
}
static const struct file_operations uio_fops = {
@@ -943,12 +1015,12 @@ void uio_unregister_device(struct uio_info *info)
uio_free_minor(idev);
+ mutex_lock(&idev->info_lock);
uio_dev_del_attributes(idev);
if (info->irq && info->irq != UIO_IRQ_CUSTOM)
free_irq(info->irq, idev);
- mutex_lock(&idev->info_lock);
idev->info = NULL;
mutex_unlock(&idev->info_lock);
--
2.20.1
On Wed, Feb 13, 2019 at 04:29:12PM +0000, Rantala, Tommi T. (Nokia - FI/Espoo) wrote:
> Backport uio fixes to 4.14, to fix use-after-free memory errors.
>
> Changed __poll_t to unsigned int as the former not found in 4.14, and
> resolved some patch context conflicts.
Thanks for this, all now queued up.
greg k-h