Tracker / CVE-2021-46904
CVE-2021-46904
In the Linux kernel, the following vulnerability has been resolved: net: hso: fix null-ptr-deref during tty device unregistration Multiple ttys try to claim the same the minor number causing a double unregistration of the same device. The first unregistration succeeds but the next one results in a null-ptr-deref. The get_free_serial_index() function returns an available minor number but doesn't assign it immediately. The assignment is done by the caller later. But before this assignment, calls to get_free_serial_index() would return the same minor number. Fix this by modifying get_free_serial_index to assign the minor number immediately after one is found to be and rename it to obtain_minor() to better reflect what it does. Similary, rename set_serial_by_index() to release_minor() and modify it to free up the minor number of the given hso_serial. Every obtain_minor() should have corresponding release_minor() call.
Affected products and versions
| linux | linux_kernel · 2.6.27 → 4.4.268 |
|---|---|
| linux | linux_kernel · 4.10.0 → 4.14.232 |
| linux | linux_kernel · 4.15.0 → 4.19.187 |
| linux | linux_kernel · 4.20.0 → 5.4.112 |
| linux | linux_kernel · 4.5.0 → 4.9.268 |
| linux | linux_kernel · 5.11.0 → 5.11.14 |
| linux | linux_kernel · 5.5.0 → 5.10.30 |