| Message ID | 20211013040438.1689277-1-yangyingliang@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | iio: buffer: check return value of kstrdup_const() | expand |
On Wed, 13 Oct 2021 12:04:38 +0800 Yang Yingliang <yangyingliang@huawei.com> wrote: > Check return value of kstrdup_const() in iio_buffer_wrap_attr(), > or it will cause null-ptr-deref in kernfs_name_hash() when calling > device_add() as follows: > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > RIP: 0010:strlen+0x0/0x20 > Call Trace: > kernfs_name_hash+0x22/0x110 > kernfs_find_ns+0x11d/0x390 > kernfs_remove_by_name_ns+0x3b/0xb0 > remove_files.isra.1+0x7b/0x190 > internal_create_group+0x7f1/0xbb0 > internal_create_groups+0xa3/0x150 > device_add+0x8f0/0x2020 > cdev_device_add+0xc3/0x160 > __iio_device_register+0x1427/0x1b40 [industrialio] > __devm_iio_device_register+0x22/0x80 [industrialio] > adjd_s311_probe+0x195/0x200 [adjd_s311] > i2c_device_probe+0xa07/0xbb0 > > Reported-by: Hulk Robot <hulkci@huawei.com> > Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") > Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Wang Wensheng sent another fix for this patch, but as that was missing the iio_attr free I have picked up this one. Applied to the fixes-togreg branch of iio.git and marked for stable. Thanks, Jonathan > --- > drivers/iio/industrialio-buffer.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index 5f4bd0b73d03..547a92d469ae 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -1312,6 +1312,11 @@ static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer, > iio_attr->buffer = buffer; > memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr)); > iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL); > + if (!iio_attr->dev_attr.attr.name) { > + kfree(iio_attr); > + return NULL; > + } > + > sysfs_attr_init(&iio_attr->dev_attr.attr); > > list_add(&iio_attr->l, &buffer->buffer_attr_list);
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 5f4bd0b73d03..547a92d469ae 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1312,6 +1312,11 @@ static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer, iio_attr->buffer = buffer; memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr)); iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL); + if (!iio_attr->dev_attr.attr.name) { + kfree(iio_attr); + return NULL; + } + sysfs_attr_init(&iio_attr->dev_attr.attr); list_add(&iio_attr->l, &buffer->buffer_attr_list);
Check return value of kstrdup_const() in iio_buffer_wrap_attr(), or it will cause null-ptr-deref in kernfs_name_hash() when calling device_add() as follows: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:strlen+0x0/0x20 Call Trace: kernfs_name_hash+0x22/0x110 kernfs_find_ns+0x11d/0x390 kernfs_remove_by_name_ns+0x3b/0xb0 remove_files.isra.1+0x7b/0x190 internal_create_group+0x7f1/0xbb0 internal_create_groups+0xa3/0x150 device_add+0x8f0/0x2020 cdev_device_add+0xc3/0x160 __iio_device_register+0x1427/0x1b40 [industrialio] __devm_iio_device_register+0x22/0x80 [industrialio] adjd_s311_probe+0x195/0x200 [adjd_s311] i2c_device_probe+0xa07/0xbb0 Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/iio/industrialio-buffer.c | 5 +++++ 1 file changed, 5 insertions(+)