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Missing Release of Memory after Effective Lifetime

CVE-2021-47173

Medium
5.5/10

Summary

In the Linux kernel, the following vulnerability has been resolved: misc/uss720: fix memory leak in uss720_probe uss720_probe forgets to decrease the refcount of usbdev in uss720_probe. Fix this by decreasing the refcount of usbdev by usb_put_dev. BUG: memory leak unreferenced object 0xffff888101113800 (size 2048): comm "kworker/0:1", pid 7, jiffies 4294956777 (age 28.870s) hex dump (first 32 bytes): ff ff ff ff 31 00 00 00 00 00 00 00 00 00 00 00 ....1........... 00 00 00 00 00 00 00 00 00 00 00 00 03 00 00 00 ................ backtrace: [<ffffffff82b8e822>] kmalloc include/linux/slab.h:554 [inline] [<ffffffff82b8e822>] kzalloc include/linux/slab.h:684 [inline] [<ffffffff82b8e822>] usb_alloc_dev+0x32/0x450 drivers/usb/core/usb.c:582 [<ffffffff82b98441>] hub_port_connect drivers/usb/core/hub.c:5129 [inline] [<ffffffff82b98441>] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] [<ffffffff82b98441>] port_event drivers/usb/core/hub.c:5509 [inline] [<ffffffff82b98441>] hub_event+0x1171/0x20c0 drivers/usb/core/hub.c:5591 [<ffffffff81259229>] process_one_work+0x2c9/0x600 kernel/workqueue.c:2275 [<ffffffff81259b19>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2421 [<ffffffff81261228>] kthread+0x178/0x1b0 kernel/kthread.c:292 [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

  • LOW
  • LOCAL
  • NONE
  • UNCHANGED
  • NONE
  • LOW
  • NONE
  • HIGH

CWE-401 - Missing release of memory after effective lifetime (memory leak)

'Missing release of memory after effective lifetime (memory leak)' is a weakness that occurs when software doesn't effectively release allocated memory after it is used. If not addressed, this enables attackers to launch denial of service attacks (by crashing or hanging the program) or take advantage of other unexpected behavior resulting from low memory conditions.

References

Advisory Timeline

  • Published