diff options
| author | Kees Cook <keescook@chromium.org> | 2023-01-13 02:03:16 +0300 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2023-01-14 02:22:03 +0300 |
| commit | 3b293487b8752cc42c1cbf8a0447bc6076c075fa (patch) | |
| tree | 7503d756954f04b7a1b354fb8bdcdc506e17f4df | |
| parent | 88603b6dc419445847923fcb7fe5080067a30f98 (diff) | |
| download | linux-3b293487b8752cc42c1cbf8a0447bc6076c075fa.tar.xz | |
firmware: coreboot: Check size of table entry and use flex-array
The memcpy() of the data following a coreboot_table_entry couldn't
be evaluated by the compiler under CONFIG_FORTIFY_SOURCE. To make it
easier to reason about, add an explicit flexible array member to struct
coreboot_device so the entire entry can be copied at once. Additionally,
validate the sizes before copying. Avoids this run-time false positive
warning:
memcpy: detected field-spanning write (size 168) of single field "&device->entry" at drivers/firmware/google/coreboot_table.c:103 (size 8)
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/all/03ae2704-8c30-f9f0-215b-7cdf4ad35a9a@molgen.mpg.de/
Cc: Jack Rosenthal <jrosenth@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Brian Norris <briannorris@chromium.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20230107031406.gonna.761-kees@kernel.org
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Link: https://lore.kernel.org/r/20230112230312.give.446-kees@kernel.org
| -rw-r--r-- | drivers/firmware/google/coreboot_table.c | 9 | ||||
| -rw-r--r-- | drivers/firmware/google/coreboot_table.h | 1 |
2 files changed, 8 insertions, 2 deletions
diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c index 2652c396c423..33ae94745aef 100644 --- a/drivers/firmware/google/coreboot_table.c +++ b/drivers/firmware/google/coreboot_table.c @@ -93,14 +93,19 @@ static int coreboot_table_populate(struct device *dev, void *ptr) for (i = 0; i < header->table_entries; i++) { entry = ptr_entry; - device = kzalloc(sizeof(struct device) + entry->size, GFP_KERNEL); + if (entry->size < sizeof(*entry)) { + dev_warn(dev, "coreboot table entry too small!\n"); + return -EINVAL; + } + + device = kzalloc(sizeof(device->dev) + entry->size, GFP_KERNEL); if (!device) return -ENOMEM; device->dev.parent = dev; device->dev.bus = &coreboot_bus_type; device->dev.release = coreboot_device_release; - memcpy(&device->entry, ptr_entry, entry->size); + memcpy(device->raw, ptr_entry, entry->size); switch (device->entry.tag) { case LB_TAG_CBMEM_ENTRY: diff --git a/drivers/firmware/google/coreboot_table.h b/drivers/firmware/google/coreboot_table.h index 37f4d335a606..d814dca33a08 100644 --- a/drivers/firmware/google/coreboot_table.h +++ b/drivers/firmware/google/coreboot_table.h @@ -79,6 +79,7 @@ struct coreboot_device { struct lb_cbmem_ref cbmem_ref; struct lb_cbmem_entry cbmem_entry; struct lb_framebuffer framebuffer; + DECLARE_FLEX_ARRAY(u8, raw); }; }; |