CVE-2024-26999
serial/pmac_zilog: Remove flawed mitigation for rx irq flood
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serial/pmac_zilog: Remove flawed mitigation for rx irq flood
In the Linux kernel, the following vulnerability has been resolved: serial/pmac_zilog: Remove flawed mitigation for rx irq flood The mitigation was intended to stop the irq completely. That may be better than a hard lock-up but it turns out that you get a crash anyway if you're using pmac_zilog as a serial console: ttyPZ0: pmz: rx irq flood ! BUG: spinlock recursion on CPU#0, swapper/0 That's because the pr_err() call in pmz_receive_chars() results in pmz_console_write() attempting to lock a spinlock already locked in pmz_interrupt(). With CONFIG_DEBUG_SPINLOCK=y, this produces a fatal BUG splat. The spinlock in question is the one in struct uart_port. Even when it's not fatal, the serial port rx function ceases to work. Also, the iteration limit doesn't play nicely with QEMU, as can be seen in the bug report linked below. A web search for other reports of the error message "pmz: rx irq flood" didn't produce anything. So I don't think this code is needed any more. Remove it.
Reserved 2024-02-19 | Published 2024-05-01 | Updated 2024-12-19 | Assigner Linuxgit.kernel.org/...c/69a02273e288011b521ee7c1f3ab2c23fda633ce
git.kernel.org/...c/d679c816929d62af51c8e6d7fc0e165c9412d2f3
git.kernel.org/...c/ab86cf6f8d24e63e9aca23da5108af1aa5483928
git.kernel.org/...c/7a3bbe41efa55323b6ea3c35fa15941d4dbecdef
git.kernel.org/...c/bbaafbb4651fede8d3c3881601ecaa4f834f9d3f
git.kernel.org/...c/52aaf1ff14622a04148dbb9ccce6d9de5d534ea7
git.kernel.org/...c/ca09dfc3cfdf89e6af3ac24e1c6c0be5c575a729
git.kernel.org/...c/1be3226445362bfbf461c92a5bcdb1723f2e4907
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