Hi Heinrich and Tom, On Sun, 26 Jan 2025 at 12:59, Tom Rini <tr...@konsulko.com> wrote:
> On Sat, Jan 04, 2025 at 12:05:24AM +0100, Heinrich Schuchardt wrote: > > On 06.12.24 18:18, Adriano Cordova wrote: > > > This commit fixes an use after free introduced in Commit e55a4acb54 > > > (" efi_loader: net: set EFI bootdevice device path to HTTP when loaded > > > from wget"). The logic in efi_net_set_dp is reworked so that when the > > > function is invoked it not only changes the value of the static > variable > > > net_dp (this is how the function was implemented in e55a4acb54) but > also > > > updates the protocol interface of the device path protocol in case efi > > > has started. > > > > > > Fixes: e55a4acb54e8 ("efi_loader: net: set EFI bootdevice device path > to HTTP when loaded from wget") > > > Signed-off-by: Adriano Cordova <adriano.cord...@canonical.com> > > > --- > > > Changes in v2: use reinstall_protocol_interface() and new_net_dp in > the body of efi_net_set_dp() > > > > > > lib/efi_loader/efi_net.c | 61 > ++++++++++++++++++++++++++++++++++------ > > > 1 file changed, 52 insertions(+), 9 deletions(-) > [snip] > > > @@ -1055,18 +1058,58 @@ out_of_resources: > > > */ > > > efi_status_t efi_net_set_dp(const char *dev, const char *server) > > > { > > > - efi_free_pool(net_dp); > > > + efi_status_t ret; > > > + struct efi_handler *phandler; > > > + struct efi_device_path *old_net_dp, *new_net_dp; > > > > > > - net_dp = NULL; > > > + old_net_dp = net_dp; > > > + new_net_dp = NULL; > > > if (!strcmp(dev, "Net")) > > > - net_dp = efi_dp_from_eth(); > > > + new_net_dp = efi_dp_from_eth(); > > > else if (!strcmp(dev, "Http")) > > > - net_dp = efi_dp_from_http(server); > > > + new_net_dp = efi_dp_from_http(server); > > > > > > - if (!net_dp) > > > + if (!new_net_dp) { > > > return EFI_OUT_OF_RESOURCES; > > > + } > > > + > > > + // If netobj is not started yet, end here. > > > + if (!netobj) { > > > + goto exit; > > > > This leads to a build failure with clang as you have not initialized > > variable ret. > > > > https://source.denx.de/u-boot/custodians/u-boot-efi/-/jobs/987832 > > > > > + } > > > + > > > + phandler = NULL; > > > + efi_search_protocol(&netobj->header, &efi_guid_device_path, > &phandler); > > > + > > > + // If the device path protocol is not yet installed, install it > > > + if (!phandler) > > > + goto add; > > > + > > > + // If it is already installed, try to update it > > > + ret = efi_reinstall_protocol_interface(&netobj->header, > &efi_guid_device_path, > > > + old_net_dp, new_net_dp); > > > + if (ret != EFI_SUCCESS) > > > + goto error; > > > + > > > + net_dp = new_net_dp; > > > + efi_free_pool(old_net_dp); > > > > > > return EFI_SUCCESS; > > > +add: > > > + ret = efi_add_protocol(&netobj->header, &efi_guid_device_path, > > > + new_net_dp); > > > + if (ret != EFI_SUCCESS) > > > + goto error; > > > +exit: > > > + net_dp = new_net_dp; > > > > Why should we set net_dp if there is no net_obj? Because the net_dp can be set before EFI starts. > > Because prior to this patch we set net_dp = NULL at the start of the > function and with this patch nothing is updating net_dp until much later > in the function. > > > Instead of jumping to exit, we can jump to error: with > > > > ret = EFI_DEVICE_ERROR. > > I'm not entirely sure what you mean by that. But can you perhaps v3 > this? I still can't re-enable CONFIG_CMD_BOOTEFI_SELFTEST on any of my > platforms due to this problem. > -- > Tom > I sent a v3. This piece of code will be replaced in the series implementing support for multiple EFI network devices, sent some days ago. Thanks, Adriano