CVE-2023-52993

x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL

State: Published
Severity: 5.5 Medium
Published: Mar 27, 2025
Updated: May 11, 2026
Reserved: Mar 27, 2025

Description

In the Linux kernel, the following vulnerability has been resolved:

x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL

Baoquan reported that after triggering a crash the subsequent crash-kernel fails to boot about half of the time. It triggers a NULL pointer dereference in the periodic tick code.

This happens because the legacy timer interrupt (IRQ0) is resent in software which happens in soft interrupt (tasklet) context. In this context get_irq_regs() returns NULL which leads to the NULL pointer dereference.

The reason for the resend is a spurious APIC interrupt on the IRQ0 vector which is captured and leads to a resend when the legacy timer interrupt is enabled. This is wrong because the legacy PIC interrupts are level triggered and therefore should never be resent in software, but nothing ever sets the IRQ_LEVEL flag on those interrupts, so the core code does not know about their trigger type.

Ensure that IRQ_LEVEL is set when the legacy PCI interrupts are set up.

Scores

CVSS	Score	Vector	Source
3.1	5.5 Medium	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H	CISA-ADP

Weaknesses

CWE-476 NULL Pointer Dereference

Affected Products

Product	Versions
LinuxLinux	a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 744fe9be9665227335539b7a77ece8d9ff62b6c0Affected a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 496975d1a2937f4baadf3d985991b13fc4fc4f27Affected a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 8770cd9d7c14aa99c255a0d08186f0be953e1638Affected a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before e284c273dbb4c1ed68d4204bff94d0b10e4a90f5Affected a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 0b08201158f177aab469e356b4d6af24fdd118dfAffected a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 137f1b47da5f58805da42c1b7811e28c1e353f39Affected a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 5fa55950729d0762a787451dc52862c3f850f859Affected
LinuxLinux	2.6.18Affected before 2.6.18Not affected 4.14.305 through 4.14.Not affected 4.19.272 through 4.19.Not affected 5.4.231 through 5.4.Not affected 5.10.166 through 5.10.Not affected 5.15.91 through 5.15.Not affected 6.1.9 through 6.1.Not affected 6.2 and laterNot affected

Product

Versions

LinuxLinux

a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 744fe9be9665227335539b7a77ece8d9ff62b6c0Affected
a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 496975d1a2937f4baadf3d985991b13fc4fc4f27Affected
a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 8770cd9d7c14aa99c255a0d08186f0be953e1638Affected
a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before e284c273dbb4c1ed68d4204bff94d0b10e4a90f5Affected
a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 0b08201158f177aab469e356b4d6af24fdd118dfAffected
a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 137f1b47da5f58805da42c1b7811e28c1e353f39Affected
a4633adcdbc15ac51afcd0e1395de58cee27cf92 to before 5fa55950729d0762a787451dc52862c3f850f859Affected

LinuxLinux

2.6.18Affected
before 2.6.18Not affected
4.14.305 through 4.14.*Not affected
4.19.272 through 4.19.*Not affected
5.4.231 through 5.4.*Not affected
5.10.166 through 5.10.*Not affected
5.15.91 through 5.15.*Not affected
6.1.9 through 6.1.*Not affected
6.2 and laterNot affected

References

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