Aaron Durbin (adurbin@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9373
-gerrit
commit 3dd3c3e7f18b1b21db06d8570572f03ae2659699 Author: Julius Werner jwerner@chromium.org Date: Fri Oct 10 14:11:11 2014 -0700
cbfs: Enforce media->map() result checking, improve error messages
If you try to boot a VBOOT2_VERIFY_FIRMWARE with less than 4K CBFS cache right now, your system will try and fail to validate the FMAP signature at (u8 *)0xFFFFFFFF and go into recovery mode. This patch avoids the memcmp() to potentially invalid memory, and also adds an error message to cbfs_simple_buffer_map() to make it explicit that we ran out of CBFS cache space.
BUG=None TEST=Booted on Veyron_Pinky with reduced CBFS cache, saw the message.
Original-Change-Id: Ic5773b4e0b36dc621513f58fc9bd29c17afbf1b7 Original-Signed-off-by: Julius Werner jwerner@chromium.org Original-Reviewed-on: https://chromium-review.googlesource.com/222899 Original-Reviewed-by: Aaron Durbin adurbin@chromium.org
(cherry picked from commit 0ed3c0c2b63be0d32e8162faf892e41cef1f1f23) Signed-off-by: Aaron Durbin adurbin@chromium.org
Change-Id: I20ccac83bff4a377caca6327d0e21032efff44c1 --- src/lib/cbfs.c | 5 ++++- src/vendorcode/google/chromeos/fmap.c | 3 ++- 2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/src/lib/cbfs.c b/src/lib/cbfs.c index fc6e887..84638da 100644 --- a/src/lib/cbfs.c +++ b/src/lib/cbfs.c @@ -175,8 +175,11 @@ void *cbfs_simple_buffer_map(struct cbfs_simple_buffer *buffer, "allocated=%zd, size=%zd, last_allocate=%zd\n", offset, count, buffer->allocated, buffer->size, buffer->last_allocate); - if (buffer->allocated + count > buffer->size) + if (buffer->allocated + count > buffer->size) { + ERROR("simple_buffer: no room to map %zd bytes from %#zx\n", + count, offset); return CBFS_MEDIA_INVALID_MAP_ADDRESS; + } if (media->read(media, address, offset, count) != count) { ERROR("simple_buffer: fail to read %zd bytes from 0x%zx\n", count, offset); diff --git a/src/vendorcode/google/chromeos/fmap.c b/src/vendorcode/google/chromeos/fmap.c index a8425c0..7c1f626 100644 --- a/src/vendorcode/google/chromeos/fmap.c +++ b/src/vendorcode/google/chromeos/fmap.c @@ -51,7 +51,8 @@ const struct fmap *fmap_find(void) media->close(media); #endif
- if (memcmp(fmap, FMAP_SIGNATURE, sizeof(FMAP_SIGNATURE)-1)) { + if (fmap == CBFS_MEDIA_INVALID_MAP_ADDRESS || + memcmp(fmap, FMAP_SIGNATURE, sizeof(FMAP_SIGNATURE) - 1)) { printk(BIOS_DEBUG, "No FMAP found at %p.\n", fmap); return NULL; }