From 03f990a5e31e28c9a2794729638f2117e028bfa5 Mon Sep 17 00:00:00 2001 From: Li Qiang Date: Fri, 21 Jun 2019 17:21:19 -0700 Subject: [PATCH] ioapic: use irq number instead of vector in ioapic_eoi_broadcast When emulating irqchip in qemu, such as following command: x86_64-softmmu/qemu-system-x86_64 -m 1024 -smp 4 -hda /home/test/test.img -machine kernel-irqchip=off --enable-kvm -vnc :0 -device edu -monitor stdio We will get a crash with following asan output: (qemu) /home/test/qemu5/qemu/hw/intc/ioapic.c:266:27: runtime error: index 35 out of bounds for type 'int [24]' ================================================================= ==113504==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61b000003114 at pc 0x5579e3c7a80f bp 0x7fd004bf8c10 sp 0x7fd004bf8c00 WRITE of size 4 at 0x61b000003114 thread T4 #0 0x5579e3c7a80e in ioapic_eoi_broadcast /home/test/qemu5/qemu/hw/intc/ioapic.c:266 #1 0x5579e3c6f480 in apic_eoi /home/test/qemu5/qemu/hw/intc/apic.c:428 #2 0x5579e3c720a7 in apic_mem_write /home/test/qemu5/qemu/hw/intc/apic.c:802 #3 0x5579e3b1e31a in memory_region_write_accessor /home/test/qemu5/qemu/memory.c:503 #4 0x5579e3b1e6a2 in access_with_adjusted_size /home/test/qemu5/qemu/memory.c:569 #5 0x5579e3b28d77 in memory_region_dispatch_write /home/test/qemu5/qemu/memory.c:1497 #6 0x5579e3a1b36b in flatview_write_continue /home/test/qemu5/qemu/exec.c:3323 #7 0x5579e3a1b633 in flatview_write /home/test/qemu5/qemu/exec.c:3362 #8 0x5579e3a1bcb1 in address_space_write /home/test/qemu5/qemu/exec.c:3452 #9 0x5579e3a1bd03 in address_space_rw /home/test/qemu5/qemu/exec.c:3463 #10 0x5579e3b8b979 in kvm_cpu_exec /home/test/qemu5/qemu/accel/kvm/kvm-all.c:2045 #11 0x5579e3ae4499 in qemu_kvm_cpu_thread_fn /home/test/qemu5/qemu/cpus.c:1287 #12 0x5579e4cbdb9f in qemu_thread_start util/qemu-thread-posix.c:502 #13 0x7fd0146376da in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da) #14 0x7fd01436088e in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x12188e This is because in ioapic_eoi_broadcast function, we uses 'vector' to index the 's->irq_eoi'. To fix this, we should uses the irq number. Signed-off-by: Li Qiang Reviewed-by: Peter Xu Message-Id: <20190622002119.126834-1-liq3ea@163.com> --- hw/intc/ioapic.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c index db9e518602..c408749876 100644 --- a/hw/intc/ioapic.c +++ b/hw/intc/ioapic.c @@ -245,8 +245,8 @@ void ioapic_eoi_broadcast(int vector) s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR; if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) { - ++s->irq_eoi[vector]; - if (s->irq_eoi[vector] >= SUCCESSIVE_IRQ_MAX_COUNT) { + ++s->irq_eoi[n]; + if (s->irq_eoi[n] >= SUCCESSIVE_IRQ_MAX_COUNT) { /* * Real hardware does not deliver the interrupt immediately * during eoi broadcast, and this lets a buggy guest make @@ -254,16 +254,16 @@ void ioapic_eoi_broadcast(int vector) * level-triggered interrupt. Emulate this behavior if we * detect an interrupt storm. */ - s->irq_eoi[vector] = 0; + s->irq_eoi[n] = 0; timer_mod_anticipate(s->delayed_ioapic_service_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + NANOSECONDS_PER_SECOND / 100); - trace_ioapic_eoi_delayed_reassert(vector); + trace_ioapic_eoi_delayed_reassert(n); } else { ioapic_service(s); } } else { - s->irq_eoi[vector] = 0; + s->irq_eoi[n] = 0; } } } -- 2.39.2