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authorWerner Pawlitschko <werner.pawlitschko@arcor.de>2015-10-27 09:08:04 +0900
committerThomas Gleixner <tglx@linutronix.de>2015-10-27 09:18:34 +0900
commitababae44108b0e94b58eef6cb5bd830bd040a47f (patch)
tree48ae676a2075db84e5c0357220d9badc33993cee
parent298a96c12b2d8fd845ae0c2c21c0a1c0b470f99e (diff)
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x86/ioapic: Prevent NULL pointer dereference in setup_ioapic_dest()
Commit 4857c91f0d19 changed the way how irq affinity is setup in setup_ioapic_dest() from using the core helper function to unconditionally calling the irq_set_affinity() callback of the underlying irq chip. That results in a NULL pointer dereference for the rare case where the underlying irq chip is lapic_chip which has no irq_set_affinity() callback. lapic_chip is occasionally used for the timer interrupt (irq 0). The fix is simple: Check the availability of the callback instead of calling it unconditionally. Fixes: 4857c91f0d19 "x86/ioapic: Force affinity setting in setup_ioapic_dest()" Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
-rw-r--r--arch/x86/kernel/apic/io_apic.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index bb6bfc01cb82..4f2821527014 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2547,7 +2547,9 @@ void __init setup_ioapic_dest(void)
mask = apic->target_cpus();
chip = irq_data_get_irq_chip(idata);
- chip->irq_set_affinity(idata, mask, false);
+ /* Might be lapic_chip for irq 0 */
+ if (chip->irq_set_affinity)
+ chip->irq_set_affinity(idata, mask, false);
}
}
#endif