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| author | Mauro Matteo Cascella <mcascell@redhat.com> | 2025-08-11 12:11:24 +0200 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2025-08-12 08:03:16 +0200 |
| commit | f757d9d90d19b914d4023663bfc4da73bbbf007e (patch) | |
| tree | 5be2a5a3b212cfb191ad3e8d6dbbb01ce6782147 | |
| parent | 624d7463043c120facfab2b54985fcfb679d5379 (diff) | |
| download | qemu-f757d9d90d19b914d4023663bfc4da73bbbf007e.zip qemu-f757d9d90d19b914d4023663bfc4da73bbbf007e.tar.gz qemu-f757d9d90d19b914d4023663bfc4da73bbbf007e.tar.bz2 | |
hw/uefi: clear uefi-vars buffer in uefi_vars_write callback
When the guest writes to register UEFI_VARS_REG_BUFFER_SIZE, the .write
callback `uefi_vars_write` is invoked. The function allocates a
heap buffer without zeroing the memory, leaving the buffer filled with
residual data from prior allocations. When the guest later reads from
register UEFI_VARS_REG_PIO_BUFFER_TRANSFER, the .read callback
`uefi_vars_read` returns leftover metadata or other sensitive process
memory from the previously allocated buffer, leading to an information
disclosure vulnerability.
Fixes: CVE-2025-8860
Fixes: 90ca4e03c27d ("hw/uefi: add var-service-core.c")
Reported-by: ZDI <zdi-disclosures@trendmicro.com>
Suggested-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Mauro Matteo Cascella <mcascell@redhat.com>
Message-ID: <20250811101128.17661-1-mcascell@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
| -rw-r--r-- | hw/uefi/var-service-core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/hw/uefi/var-service-core.c b/hw/uefi/var-service-core.c index feec5a5..6ab8df0 100644 --- a/hw/uefi/var-service-core.c +++ b/hw/uefi/var-service-core.c @@ -259,8 +259,8 @@ static void uefi_vars_write(void *opaque, hwaddr addr, uint64_t val, unsigned si uv->buf_size = val; g_free(uv->buffer); g_free(uv->pio_xfer_buffer); - uv->buffer = g_malloc(uv->buf_size); - uv->pio_xfer_buffer = g_malloc(uv->buf_size); + uv->buffer = g_malloc0(uv->buf_size); + uv->pio_xfer_buffer = g_malloc0(uv->buf_size); break; case UEFI_VARS_REG_DMA_BUFFER_ADDR_LO: uv->buf_addr_lo = val; |