wmi_dev_probe() allocates one byte less than necessary, thus subsequent sprintf() call writes trailing zero past the end of the 'buf':

BUG: KASAN: slab-out-of-bounds in vsnprintf+0xda4/0x1240 Write of size 1 at addr ffff880423529caf by task kworker/1:1/32

Call Trace: dump_stack+0xb3/0x14d print_address_description+0xd7/0x380 kasan_report+0x166/0x2b0 vsnprintf+0xda4/0x1240 sprintf+0x9b/0xd0 wmi_dev_probe+0x1c3/0x400 driver_probe_device+0x5d1/0x990 bus_for_each_drv+0x109/0x190 __device_attach+0x217/0x360 bus_probe_device+0x1ad/0x260 deferred_probe_work_func+0x10f/0x5d0 process_one_work+0xa8b/0x1dc0 worker_thread+0x20d/0x17d0 kthread+0x311/0x3d0 ret_from_fork+0x3a/0x50

Allocated by task 32: kasan_kmalloc+0xa0/0xd0 __kmalloc+0x14f/0x3e0 wmi_dev_probe+0x182/0x400 driver_probe_device+0x5d1/0x990 bus_for_each_drv+0x109/0x190 __device_attach+0x217/0x360 bus_probe_device+0x1ad/0x260 deferred_probe_work_func+0x10f/0x5d0 process_one_work+0xa8b/0x1dc0 worker_thread+0x20d/0x17d0 kthread+0x311/0x3d0 ret_from_fork+0x3a/0x50

Increment allocation size to fix this.

Fixes: 44b6b7661132 ("platform/x86: wmi: create userspace interface for drivers") Signed-off-by: Andrey Ryabinin aryabinin@virtuozzo.com Cc: stable@vger.kernel.org --- drivers/platform/x86/wmi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index daa68acbc900..c0c8945603cb 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -933,7 +933,7 @@ static int wmi_dev_probe(struct device *dev) goto probe_failure; }

- buf = kmalloc(strlen(wdriver->driver.name) + 4, GFP_KERNEL); + buf = kmalloc(strlen(wdriver->driver.name) + 5, GFP_KERNEL); if (!buf) { ret = -ENOMEM; goto probe_string_failure;