Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 74ea66d4ca061a3cd4c0e924e51b60e924644852 before e22a97700901ba5e8bf8db68056a0d50f9440cae; affected 74ea66d4ca061a3cd4c0e924e51b60e924644852 before de5bd24197bd9ee37ec1e379a3d882bbd15c5065; affected 74ea66d4ca061a3cd4c0e924e51b60e924644852 before 8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c; affected 74ea66d4ca061a3cd4c0e924e51b60e924644852 before 9b88a7c4584ba67267a051069b8abe44fc9595b2; affected 74ea66d4ca061a3cd4c0e924e51b60e924644852 before 4410dba9807a17a93f649a9f5870ceaf30a675a3; affected 74ea66d4ca061a3cd4c0e924e51b60e924644852 before b06f388994500297bb91be60ffaf6825ecfd2afe |
| Linux / Linux | affected 4.6; unaffected 0 before 4.6; unaffected 5.15.179 through 5.15.*; unaffected 6.1.129 through 6.1.*; unaffected 6.6.78 through 6.6.*; unaffected 6.12.14 through 6.12.*; unaffected 6.13.3 through 6.13.*; unaffected 6.14 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/e22a97700901ba5e8bf8db68056a0d50f9440cae
- https://git.kernel.org/stable/c/de5bd24197bd9ee37ec1e379a3d882bbd15c5065
- https://git.kernel.org/stable/c/8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c
- https://git.kernel.org/stable/c/9b88a7c4584ba67267a051069b8abe44fc9595b2
- https://git.kernel.org/stable/c/4410dba9807a17a93f649a9f5870ceaf30a675a3
- https://git.kernel.org/stable/c/b06f388994500297bb91be60ffaf6825ecfd2afe
ADP enrichment
No English description supplied.