In e820_add_entry() the e820_table is reallocated with g_renew() to make
space for a new entry. However, fw_cfg_arch_create() just uses the
existing e820_table pointer. This leads to a use-after-free if anything
adds a new entry after fw_cfg is set up.
Shift the addition of the etc/e820 file to the machine done notifier, via
a new fw_cfg_add_e820() function.
Also make e820_table private and use an e820_get_table() accessor function
for it, which sets a flag that will trigger an assert() for any *later*
attempts to add to the table.
Make e820_add_entry() return void, as most callers don't check for error
anyway.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <a2708734f004b224f33d3b4824e9a5a262431568.camel@infradead.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
e820 reserved entries were used before the dynamic entries with fw config files
were intoduced. Please see the following change:
7d67110f2d9a6("pc: add etc/e820 fw_cfg file")
Identical support was introduced into seabios as well with the following commit:
ce39bd4031820 ("Add support for etc/e820 fw_cfg file")
Both the above commits are now quite old. QEMU machines 1.7 and newer no longer
use the reserved entries. Seabios uses fw config files and
dynamic e820 entries by default and only falls back to using reserved entries
when it has to work with old qemu (versions earlier than 1.7). Please see
functions qemu_cfg_e820() and qemu_early_e820(). It is safe to remove legacy
FW_CFG_E820_TABLE and associated code now as QEMU 7.0 has deprecated i440fx
machines 1.7 and older. It would be incredibly rare to run the latest qemu
version with a very old version of seabios that did not support fw config files
for e820.
As far as I could see, edk2/ovfm never supported reserved entries and uses fw
config files from the beginning. So there should be no incompatibilities with
ovfm as well.
CC: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Ani Sinha <ani@anisinha.ca>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20220831045311.33083-1-ani@anisinha.ca>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Suggested-by: Samuel Ortiz <sameo@linux.intel.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190818225414.22590-3-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
