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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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4fb60b158a
The EFI platform firmware fallback would clobber any pre-allocated
buffers. Instead, correctly refuse to reallocate when too small (as
already done in the sysfs fallback), or perform allocation normally
when needed.
Fixes: e4c2c0ff00 ("firmware: Add new platform fallback mechanism and firmware_request_platform()")
Cc: stable@vger.kernel.org
Acked-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200724213640.389191-4-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
40 lines
858 B
C
40 lines
858 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/efi_embedded_fw.h>
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#include <linux/property.h>
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#include <linux/security.h>
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#include <linux/vmalloc.h>
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#include "fallback.h"
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#include "firmware.h"
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int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
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{
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const u8 *data;
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size_t size;
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int rc;
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if (!(opt_flags & FW_OPT_FALLBACK_PLATFORM))
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return -ENOENT;
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rc = security_kernel_load_data(LOADING_FIRMWARE_EFI_EMBEDDED);
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if (rc)
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return rc;
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rc = efi_get_embedded_fw(fw_priv->fw_name, &data, &size);
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if (rc)
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return rc; /* rc == -ENOENT when the fw was not found */
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if (fw_priv->data && size > fw_priv->allocated_size)
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return -ENOMEM;
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if (!fw_priv->data)
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fw_priv->data = vmalloc(size);
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if (!fw_priv->data)
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return -ENOMEM;
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memcpy(fw_priv->data, data, size);
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fw_priv->size = size;
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fw_state_done(fw_priv);
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return 0;
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}
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