CVE-2024-26999

serial/pmac_zilog: Remove flawed mitigation for rx irq flood

State: Published
Severity: Not scored
Published: May 1, 2024
Updated: May 11, 2026
Reserved: Feb 19, 2024

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 69a02273e288011b521ee7c1f3ab2c23fda633ceAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before d679c816929d62af51c8e6d7fc0e165c9412d2f3Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before ab86cf6f8d24e63e9aca23da5108af1aa5483928Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 7a3bbe41efa55323b6ea3c35fa15941d4dbecdefAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before bbaafbb4651fede8d3c3881601ecaa4f834f9d3fAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 52aaf1ff14622a04148dbb9ccce6d9de5d534ea7Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before ca09dfc3cfdf89e6af3ac24e1c6c0be5c575a729Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 1be3226445362bfbf461c92a5bcdb1723f2e4907Affected
LinuxLinux	2.6.12Affected before 2.6.12Not affected 4.19.313 through 4.19.Not affected 5.4.275 through 5.4.Not affected 5.10.216 through 5.10.Not affected 5.15.157 through 5.15.Not affected 6.1.88 through 6.1.Not affected 6.6.29 through 6.6.Not affected 6.8.8 through 6.8.*Not affected 6.9 and laterNot affected

Product

Versions

LinuxLinux

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 69a02273e288011b521ee7c1f3ab2c23fda633ceAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before d679c816929d62af51c8e6d7fc0e165c9412d2f3Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before ab86cf6f8d24e63e9aca23da5108af1aa5483928Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 7a3bbe41efa55323b6ea3c35fa15941d4dbecdefAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before bbaafbb4651fede8d3c3881601ecaa4f834f9d3fAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 52aaf1ff14622a04148dbb9ccce6d9de5d534ea7Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before ca09dfc3cfdf89e6af3ac24e1c6c0be5c575a729Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 1be3226445362bfbf461c92a5bcdb1723f2e4907Affected

LinuxLinux

2.6.12Affected
before 2.6.12Not affected
4.19.313 through 4.19.*Not affected
5.4.275 through 5.4.*Not affected
5.10.216 through 5.10.*Not affected
5.15.157 through 5.15.*Not affected
6.1.88 through 6.1.*Not affected
6.6.29 through 6.6.*Not affected
6.8.8 through 6.8.*Not affected
6.9 and laterNot affected

References

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