diff options
| author | Werner Pawlitschko <werner.pawlitschko@arcor.de> | 2015-10-27 09:08:04 +0900 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-10-27 09:18:34 +0900 |
| commit | ababae44108b0e94b58eef6cb5bd830bd040a47f (patch) | |
| tree | 48ae676a2075db84e5c0357220d9badc33993cee | |
| parent | 298a96c12b2d8fd845ae0c2c21c0a1c0b470f99e (diff) | |
| download | linux-ababae44108b0e94b58eef6cb5bd830bd040a47f.tar.gz linux-ababae44108b0e94b58eef6cb5bd830bd040a47f.tar.bz2 linux-ababae44108b0e94b58eef6cb5bd830bd040a47f.zip | |
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.c | 4 |
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 |