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qemu/hw/isa
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Philippe Mathieu-Daudé 4177b062fc hw/isa/lpc_ich9: Ignore reserved/invalid SCI IRQ 
libFuzzer triggered the following assertion:

  cat << EOF | qemu-system-i386 -M pc-q35-5.0 \
    -nographic -monitor none -serial none \
    -qtest stdio -d guest_errors -trace pci\*
  outl 0xcf8 0x8400f841
  outl 0xcfc 0xebed205d
  outl 0x5d02 0xedf82049
  EOF
  pci_cfg_write ICH9-LPC 31:0 @0x41 <- 0xebed205d
  hw/pci/pci.c:268: int pci_bus_get_irq_level(PCIBus *, int): Assertion `irq_num < bus->nirq' failed.

This is because ich9_lpc_sci_irq() returns -1 for reserved
(illegal) values, but ich9_lpc_pmbase_sci_update() considers
it valid and store it in a 8-bit unsigned type. Then the 255
value is used as GSI IRQ, resulting in a PIRQ value of 247,
more than ICH9_LPC_NB_PIRQS (8).

Fix by simply ignoring the invalid access (and reporting it):

  pci_cfg_write ICH9-LPC 31:0 @0x41 <- 0xebed205d
  ICH9 LPC: SCI IRQ SEL #3 is reserved
  pci_cfg_read mch 00:0 @0x0 -> 0x8086
  pci_cfg_read mch 00:0 @0x0 -> 0x29c08086
  ...

Cc: qemu-stable@nongnu.org
Reported-by: Alexander Bulekov <alxndr@bu.edu>
Fixes: 8f242cb724 ("ich9: implement SCI_IRQ_SEL register")
BugLink: https://bugs.launchpad.net/qemu/+bug/1878642
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200717151705.18611-1-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-03 09:42:53 -05:00
..
apm.c hw/isa/apm: Convert debug printf()s to trace events 2020-06-09 19:05:20 +02:00
i82378.c Use OBJECT_DECLARE_SIMPLE_TYPE when possible 2020-09-18 14:12:32 -04:00
isa-bus.c hw/isa/isa-bus: Replace hw_error() by assert() 2020-09-09 15:25:28 +02:00
isa-superio.c hw/isa/isa-superio: Fix IDE controller realization 2020-09-01 09:02:37 +02:00
Kconfig hw/input: Do not enable CONFIG_PCKBD by default 2020-02-04 09:01:31 +01:00
lpc_ich9.c hw/isa/lpc_ich9: Ignore reserved/invalid SCI IRQ 2020-11-03 09:42:53 -05:00
meson.build meson: convert hw/isa 2020-08-21 06:30:29 -04:00
pc87312.c pc87312: Rename TYPE_PC87312_SUPERIO to TYPE_PC87312 2020-09-09 13:20:22 -04:00
piix3.c piix: Move QOM macros to header 2020-08-27 14:04:55 -04:00
piix4.c Use OBJECT_DECLARE_SIMPLE_TYPE when possible 2020-09-18 14:12:32 -04:00
smc37c669-superio.c hw/isa/superio: Correct the license text 2020-04-01 19:00:16 +02:00
trace-events hw/isa/apm: Convert debug printf()s to trace events 2020-06-09 19:05:20 +02:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
vt82c686.c Use OBJECT_DECLARE_SIMPLE_TYPE when possible 2020-09-18 14:12:32 -04:00