From: Markos Chandras Date: Mon, 23 Jun 2014 08:48:51 +0000 (+0100) Subject: MIPS: MSC: Prevent out-of-bounds writes to MIPS SC ioremap'd region X-Git-Tag: firefly_0821_release~176^2~3687^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ab6c15bc6620ebe220970cc040b29bcb2757f373;p=firefly-linux-kernel-4.4.55.git MIPS: MSC: Prevent out-of-bounds writes to MIPS SC ioremap'd region Previously, the lower limit for the MIPS SC initialization loop was set incorrectly allowing one extra loop leading to writes beyond the MSC ioremap'd space. More precisely, the value of the 'imp' in the last loop increased beyond the msc_irqmap_t boundaries and as a result of which, the 'n' variable was loaded with an incorrect value. This value was used later on to calculate the offset in the MSC01_IC_SUP which led to random crashes like the following one: CPU 0 Unable to handle kernel paging request at virtual address e75c0200, epc == 8058dba4, ra == 8058db90 [...] Call Trace: [<8058dba4>] init_msc_irqs+0x104/0x154 [<8058b5bc>] arch_init_irq+0xd8/0x154 [<805897b0>] start_kernel+0x220/0x36c Kernel panic - not syncing: Attempted to kill the idle task! This patch fixes the problem Signed-off-by: Markos Chandras Reviewed-by: James Hogan Cc: stable@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7118/ Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/kernel/irq-msc01.c b/arch/mips/kernel/irq-msc01.c index 4858642d543d..a734b2c2f9ea 100644 --- a/arch/mips/kernel/irq-msc01.c +++ b/arch/mips/kernel/irq-msc01.c @@ -126,7 +126,7 @@ void __init init_msc_irqs(unsigned long icubase, unsigned int irqbase, msc_irqma board_bind_eic_interrupt = &msc_bind_eic_interrupt; - for (; nirq >= 0; nirq--, imp++) { + for (; nirq > 0; nirq--, imp++) { int n = imp->im_irq; switch (imp->im_type) {