serial: protect uart_port_dtr_rts() in uart_shutdown() too

Summary

In the Linux kernel, the following vulnerability has been resolved: serial: protect uart_port_dtr_rts() in uart_shutdown() too Commit af224ca2df29 (serial: core: Prevent unsafe uart port access, part 3) added few uport == NULL checks. It added one to uart_shutdown(), so the commit assumes, uport can be NULL in there. But right after that protection, there is an unprotected "uart_port_dtr_rts(uport, false);" call. That is invoked only if HUPCL is set, so I assume that is the reason why we do not see lots of these reports. Or it cannot be NULL at this point at all for some reason :P. Until the above is investigated, stay on the safe side and move this dereference to the if too. I got this inconsistency from Coverity under CID 1585130. Thanks.

Timeline

1. Oct 21, 2024, 7:39 PM UTCCVE published
2. Oct 22, 2024, 1:23 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Oct 15, 2026, 12:56 AM UTCRecord last updated

Affected versions

• Linux Linux

  From af224ca2df297440448b9d407d21b50982c6d532 · fixed in 2fe399bb8efd0d325ab1138cf8e3ecf23a39e96d; From af224ca2df297440448b9d407d21b50982c6d532 · fixed in 399927f0f875b93f3d5a0336d382ba48b8671eb2; From af224ca2df297440448b9d407d21b50982c6d532 · fixed in d7b5876a6e74cdf8468a478be6b23f2f5464ac7a; From af224ca2df297440448b9d407d21b50982c6d532 · fixed in e418d91195d29d5f9c9685ff309b92b04b41dc40; From af224ca2df297440448b9d407d21b50982c6d532 · fixed in 76ed24a34223bb2c6b6162e1d8389ec4e602a290; From af224ca2df297440448b9d407d21b50982c6d532 · fixed in 602babaa84d627923713acaf5f7e9a4369e77473

• Linux Linux

  4.7

• KernelLinux

  From 4.7.0 · fixed in 5.10.229; From 5.11.0 · fixed in 5.15.170; From 5.16.0 · fixed in 6.1.115; From 6.2.0 · fixed in 6.6.57; From 6.7.0 · fixed in 6.11.4

References 6