Description
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.
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
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 69a02273e288011b521ee7c1f3ab2c23fda633ceaffected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < d679c816929d62af51c8e6d7fc0e165c9412d2f3affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < ab86cf6f8d24e63e9aca23da5108af1aa5483928affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 7a3bbe41efa55323b6ea3c35fa15941d4dbecdefaffected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < bbaafbb4651fede8d3c3881601ecaa4f834f9d3faffected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 52aaf1ff14622a04148dbb9ccce6d9de5d534ea7affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < ca09dfc3cfdf89e6af3ac24e1c6c0be5c575a729affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 1be3226445362bfbf461c92a5bcdb1723f2e4907affected
Linux Linux
Default version status: affected
2.6.12affected0 to < 2.6.12unaffected4.19.313 to ≤ 4.19.*unaffected5.4.275 to ≤ 5.4.*unaffected5.10.216 to ≤ 5.10.*unaffected5.15.157 to ≤ 5.15.*unaffected6.1.88 to ≤ 6.1.*unaffected6.6.29 to ≤ 6.6.*unaffected6.8.8 to ≤ 6.8.*unaffected6.9 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/69a02273e288011b521ee7c1f3ab2c23fda633ce ↗
- https://git.kernel.org/stable/c/d679c816929d62af51c8e6d7fc0e165c9412d2f3 ↗
- https://git.kernel.org/stable/c/ab86cf6f8d24e63e9aca23da5108af1aa5483928 ↗
- https://git.kernel.org/stable/c/7a3bbe41efa55323b6ea3c35fa15941d4dbecdef ↗
- https://git.kernel.org/stable/c/bbaafbb4651fede8d3c3881601ecaa4f834f9d3f ↗
- https://git.kernel.org/stable/c/52aaf1ff14622a04148dbb9ccce6d9de5d534ea7 ↗
- https://git.kernel.org/stable/c/ca09dfc3cfdf89e6af3ac24e1c6c0be5c575a729 ↗
- https://git.kernel.org/stable/c/1be3226445362bfbf461c92a5bcdb1723f2e4907 ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html ↗
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DAMSOZXJEPUOXW33WZYWCVAY7Z5S7OOY/ ↗
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EZ6PJW7VOZ224TD7N4JZNU6KV32ZJ53/ ↗
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GCBZZEC7L7KTWWAS2NLJK6SO3IZIL4WW/ ↗