Bug 2536212 (CVE-2026-90124) - CVE-2026-90124 kernel: irqchip/renesas-rzg2l: Fix loss of interrupt
Summary: CVE-2026-90124 kernel: irqchip/renesas-rzg2l: Fix loss of interrupt
Keywords:
Status: NEW
Alias: CVE-2026-90124
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 16:54 UTC by OSIDB Bzimport
Modified: 2026-10-13 12:46 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-09-17 16:54:23 UTC
In the Linux kernel, the following vulnerability has been resolved:

irqchip/renesas-rzg2l: Fix loss of interrupt

rzg2l_clear_irq_int() and rzg2l_clear_tint_int() perform a
read-modify-write on the ISCR/TSCR status registers to clear the bit
for the interrupt just handled. Since these registers are
write-0-to-clear per bit, this is racy:

If another interrupt's status bit gets set between the read and the write,
that bit is written back as 0 by the software-constructed value, clearing
an interrupt that hasn't been serviced yet and losing it.

This can be reproduced by triggering multiple interrupts at once, e.g.:

  gpioset -c gpiochip0 355=0 353=0 328=0 352=0

Fix this by writing back only the bit being cleared, with all other bits
set to 1, instead of read-modify-writing the whole register.  Since 1-bits
are left unchanged by hardware, concurrently-set status bits for other
interrupts are preserved.


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