Re: [PATCH] powerpc/interrupt: Fix OOPS by not calling do_IRQ() from timer_interrupt()
From: Michael Ellerman
Date: Fri Aug 13 2021 - 07:59:08 EST
On Tue, 10 Aug 2021 16:13:16 +0000 (UTC), Christophe Leroy wrote:
> An interrupt handler shall not be called from another interrupt
> handler otherwise this leads to problems like the following:
>
> Kernel attempted to write user page (afd4fa84) - exploit attempt? (uid: 1000)
> ------------[ cut here ]------------
> Bug: Write fault blocked by KUAP!
> WARNING: CPU: 0 PID: 1617 at arch/powerpc/mm/fault.c:230 do_page_fault+0x484/0x720
> Modules linked in:
> CPU: 0 PID: 1617 Comm: sshd Tainted: G W 5.13.0-pmac-00010-g8393422eb77 #7
> NIP: c001b77c LR: c001b77c CTR: 00000000
> REGS: cb9e5bc0 TRAP: 0700 Tainted: G W (5.13.0-pmac-00010-g8393422eb77)
> MSR: 00021032 <ME,IR,DR,RI> CR: 24942424 XER: 00000000
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/interrupt: Fix OOPS by not calling do_IRQ() from timer_interrupt()
https://git.kernel.org/powerpc/c/98694166c27d473c36b434bd3572934c2f2a16ab
cheers