Description
In the Linux kernel, the following vulnerability has been resolved: media: as102: fix to not free memory after the device is registered in as102_usb_probe() In as102_usb driver, the following race condition occurs: ``` CPU0 CPU1 as102_usb_probe() kzalloc(); // alloc as102_dev_t .... usb_register_dev(); fd = sys_open("/path/to/dev"); // open as102 fd .... usb_deregister_dev(); .... kfree(); // free as102_dev_t .... sys_close(fd); as102_release() // UAF!! as102_usb_release() kfree(); // DFB!! ``` When a USB character device registered with usb_register_dev() is later unregistered (via usb_deregister_dev() or disconnect), the device node is removed so new open() calls fail. However, file descriptors that are already open do not go away immediately: they remain valid until the last reference is dropped and the driver's .release() is invoked. In as102, as102_usb_probe() calls usb_register_dev() and then, on an error path, does usb_deregister_dev() and frees as102_dev_t right away. If userspace raced a successful open() before the deregistration, that open FD will later hit as102_release() --> as102_usb_release() and access or free as102_dev_t again, occur a race to use-after-free and double-free vuln. The fix is to never kfree(as102_dev_t) directly once usb_register_dev() has succeeded. After deregistration, defer freeing memory to .release(). In other words, let release() perform the last kfree when the final open FD is closed.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 0d36653a3a821e5a974798adb347b3ea09332914affectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 25d500cf391e384356a612b85cf60b353ad3cd0caffectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 07ceb444c8f627cf863864d4274b5a77769725edaffectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < cb8092038e95dc1113a68e63762de40fff61ba71affectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 582fbecb3756330006fe1950762412a68c2cacd2affectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 09e9206008b887aa553733bd915d73131071a086affectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 2eeae47a438694408189138048a786be99954032affectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 7e5aedf6059cba2a669d86caeaf5a51f33ec85a1affectedcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c to < 8bd29dbe03fc5b0f039ab2395ff37b64236d2f0caffected
Linux Linux
Default version status: affected
3.14affected0 to < 3.14unaffected5.10.258 to ≤ 5.10.*unaffected5.15.209 to ≤ 5.15.*unaffected6.1.175 to ≤ 6.1.*unaffected6.6.136 to ≤ 6.6.*unaffected6.12.83 to ≤ 6.12.*unaffected6.18.24 to ≤ 6.18.*unaffected6.19.14 to ≤ 6.19.*unaffected7.0.1 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/0d36653a3a821e5a974798adb347b3ea09332914 ↗
- https://git.kernel.org/stable/c/25d500cf391e384356a612b85cf60b353ad3cd0c ↗
- https://git.kernel.org/stable/c/07ceb444c8f627cf863864d4274b5a77769725ed ↗
- https://git.kernel.org/stable/c/cb8092038e95dc1113a68e63762de40fff61ba71 ↗
- https://git.kernel.org/stable/c/582fbecb3756330006fe1950762412a68c2cacd2 ↗
- https://git.kernel.org/stable/c/09e9206008b887aa553733bd915d73131071a086 ↗
- https://git.kernel.org/stable/c/2eeae47a438694408189138048a786be99954032 ↗
- https://git.kernel.org/stable/c/7e5aedf6059cba2a669d86caeaf5a51f33ec85a1 ↗
- https://git.kernel.org/stable/c/8bd29dbe03fc5b0f039ab2395ff37b64236d2f0c ↗