[Qemu-commits] [qemu/qemu] f2609f: i2c: pm_smbus: check smb_index before block transf...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: f2609ffdf39bcd4f89b5f67b33347490023a7a84
      
https://github.com/qemu/qemu/commit/f2609ffdf39bcd4f89b5f67b33347490023a7a84
  Author: Prasad J Pandit <address@hidden>
  Date:   2018-12-06 (Thu, 06 Dec 2018)

  Changed paths:
    M hw/i2c/pm_smbus.c

  Log Message:
  -----------
  i2c: pm_smbus: check smb_index before block transfer write

While performing block transfer write in smb_ioport_writeb(),
'smb_index' is incremented and used to index smb_data[] array.
Check 'smb_index' value to avoid OOB access.

Note that this bug is exploitable by a guest to escape
from the virtual machine. However the commit which
introduced the bug was only made after the 3.0 release,
and so it is not present in any released QEMU versions.

Fixes: 38ad4fae43 i2c: pm_smbus: Add block transfer capability
Reported-by: Michael Hanselmann <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>
Reviewed-by: Li Qiang <address@hidden>
Reviewed-by: Michael Hanselmann <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Message-id: address@hidden
Signed-off-by: Peter Maydell <address@hidden>



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