[PULL V2 31/33] hw/net/e1000e: Do not abort() on invalid PSRCTL register value

[Jason Wang]

From: Philippe Mathieu-Daudé <f4bug@amsat.org>

libFuzzer found using 'qemu-system-i386 -M q35':

qemu: hardware error: e1000e: PSRCTL.BSIZE0 cannot be zero
CPU #0:
EAX=00000000 EBX=00000000 ECX=00000000 EDX=00000663
ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
EIP=0000fff0 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300
CS =f000 ffff0000 0000ffff 00009b00
SS =0000 00000000 0000ffff 00009300
DS =0000 00000000 0000ffff 00009300
FS =0000 00000000 0000ffff 00009300
GS =0000 00000000 0000ffff 00009300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 0000ffff
IDT=     00000000 0000ffff
CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000
DR6=ffff0ff0 DR7=00000400
EFER=0000000000000000
FCW=037f FSW=0000 [ST=0] FTW=00 MXCSR=00001f80
FPR0=0000000000000000 0000 FPR1=0000000000000000 0000
FPR2=0000000000000000 0000 FPR3=0000000000000000 0000
FPR4=0000000000000000 0000 FPR5=0000000000000000 0000
FPR6=0000000000000000 0000 FPR7=0000000000000000 0000
XMM00=00000000000000000000000000000000 XMM01=00000000000000000000000000000000
XMM02=00000000000000000000000000000000 XMM03=00000000000000000000000000000000
XMM04=00000000000000000000000000000000 XMM05=00000000000000000000000000000000
XMM06=00000000000000000000000000000000 XMM07=00000000000000000000000000000000
==1988== ERROR: libFuzzer: deadly signal
    #6 0x7fae4d3ea894 in __GI_abort (/lib64/libc.so.6+0x22894)
    #7 0x563f4cc59a1d in hw_error (qemu-fuzz-i386+0xe8ca1d)
    #8 0x563f4d7c93f2 in e1000e_set_psrctl (qemu-fuzz-i386+0x19fc3f2)
    #9 0x563f4d7b798f in e1000e_core_write (qemu-fuzz-i386+0x19ea98f)
    #10 0x563f4d7afc46 in e1000e_mmio_write (qemu-fuzz-i386+0x19e2c46)
    #11 0x563f4cc9a0a7 in memory_region_write_accessor (qemu-fuzz-i386+0xecd0a7)
    #12 0x563f4cc99c13 in access_with_adjusted_size (qemu-fuzz-i386+0xeccc13)
    #13 0x563f4cc987b4 in memory_region_dispatch_write (qemu-fuzz-i386+0xecb7b4)

It simply sent the following 2 I/O command to the e1000e
PCI BAR #2 I/O region:

  writew 0x0100 0x0c00 # RCTL =   E1000_RCTL_DTYP_MASK
  writeb 0x2170 0x00   # PSRCTL = 0

2813 static void
2814 e1000e_set_psrctl(E1000ECore *core, int index, uint32_t val)
2815 {
2816     if (core->mac[RCTL] & E1000_RCTL_DTYP_MASK) {
2817
2818         if ((val & E1000_PSRCTL_BSIZE0_MASK) == 0) {
2819             hw_error("e1000e: PSRCTL.BSIZE0 cannot be zero");
2820         }

Instead of calling hw_error() which abort the process (it is
meant for CPU fatal error condition, not for device logging),
log the invalid request with qemu_log_mask(LOG_GUEST_ERROR)
and return, ignoring the request.

Cc: qemu-stable@nongnu.org
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/e1000e_core.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
index d567687..bcd186c 100644
--- a/hw/net/e1000e_core.c
+++ b/hw/net/e1000e_core.c
@@ -34,9 +34,9 @@
 */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "net/net.h"
 #include "net/tap.h"
-#include "hw/hw.h"
 #include "hw/pci/msi.h"
 #include "hw/pci/msix.h"
 #include "sysemu/runstate.h"
@@ -2816,11 +2816,15 @@ e1000e_set_psrctl(E1000ECore *core, int index, uint32_t 
val)
     if (core->mac[RCTL] & E1000_RCTL_DTYP_MASK) {
 
         if ((val & E1000_PSRCTL_BSIZE0_MASK) == 0) {
-            hw_error("e1000e: PSRCTL.BSIZE0 cannot be zero");
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "e1000e: PSRCTL.BSIZE0 cannot be zero");
+            return;
         }
 
         if ((val & E1000_PSRCTL_BSIZE1_MASK) == 0) {
-            hw_error("e1000e: PSRCTL.BSIZE1 cannot be zero");
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "e1000e: PSRCTL.BSIZE1 cannot be zero");
+            return;
         }
     }
 
-- 
2.5.0