| Message ID | 20211011125846.66553-1-wangwensheng4@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [-next] iio: buffer: Check the return value of kstrdup_const() | expand |
On Mon, 11 Oct 2021 12:58:46 +0000 Wang Wensheng <wangwensheng4@huawei.com> wrote: > We should check the duplication of attr.name properly in > iio_buffer_wrap_attr() or a null-pointer-dereference would > occur on destroying the related sysfs file. > This issue is found by fault-injection. > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > PGD 0 P4D 0 > Oops: 0000 [#1] SMP PTI > RIP: 0010:strlen+0x0/0x20 > Call Trace: > kernfs_name_hash+0x1c/0xb0 > kernfs_find_ns+0xc6/0x160 > kernfs_remove_by_name_ns+0x5c/0xb0 > remove_files.isra.1+0x42/0x90 > internal_create_group+0x42f/0x460 > internal_create_groups+0x49/0xc0 > device_add+0xb5b/0xbe0 > ? kobject_get+0x90/0xa0 > cdev_device_add+0x2b/0x90 > __iio_device_register+0xa56/0xb40 > > Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") > Reported-by: Hulk Robot<hulkci@huawei.com> > Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> This version seems to be a duplicate with the version Yang Yingliang sent a few days later, but that version has the free of the iio_attr which is missing here. Thanks, Jonathan > --- > drivers/iio/industrialio-buffer.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index c648e9553edd..f4011c477bac 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -1312,6 +1312,8 @@ 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) > + 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 c648e9553edd..f4011c477bac 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1312,6 +1312,8 @@ 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) + return NULL; sysfs_attr_init(&iio_attr->dev_attr.attr); list_add(&iio_attr->l, &buffer->buffer_attr_list);
We should check the duplication of attr.name properly in iio_buffer_wrap_attr() or a null-pointer-dereference would occur on destroying the related sysfs file. This issue is found by fault-injection. BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI RIP: 0010:strlen+0x0/0x20 Call Trace: kernfs_name_hash+0x1c/0xb0 kernfs_find_ns+0xc6/0x160 kernfs_remove_by_name_ns+0x5c/0xb0 remove_files.isra.1+0x42/0x90 internal_create_group+0x42f/0x460 internal_create_groups+0x49/0xc0 device_add+0xb5b/0xbe0 ? kobject_get+0x90/0xa0 cdev_device_add+0x2b/0x90 __iio_device_register+0xa56/0xb40 Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr") Reported-by: Hulk Robot<hulkci@huawei.com> Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> --- drivers/iio/industrialio-buffer.c | 2 ++ 1 file changed, 2 insertions(+)