[U-Boot] [PATCH] disk: Fix possible out-of-bounds access in part_efi.c

Make sure to never access beyond bounds of either EFI partition name or DOS partition name. This situation is happening:
part.h: disk_partition_t->name is 32-byte long part_efi.h: gpt_entry->partition_name is 36-bytes long
The loop in part_efi.c copies over 36 bytes and thus accesses beyond the disk_partition_t->name .
Fix this by picking the shortest of source and destination arrays and make sure the destination array is cleared so the trailing bytes are zeroed-out and don't cause issues with string manipulation.
Signed-off-by: Marek Vasut marex@denx.de Cc: Tom Rini trini@ti.com Cc: Simon Glass sjg@chromium.org --- disk/part_efi.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
NOTE: I didn't test this patch on real hardware! Please review and test if possible.
diff --git a/disk/part_efi.c b/disk/part_efi.c index e9987f0..8753aea 100644 --- a/disk/part_efi.c +++ b/disk/part_efi.c @@ -373,7 +373,7 @@ int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e, u32 offset = (u32)le32_to_cpu(gpt_h->first_usable_lba); ulong start; int i, k; - size_t name_len; + size_t efiname_len, dosname_len; #ifdef CONFIG_PARTITION_UUIDS char *str_uuid; #endif @@ -421,9 +421,14 @@ int gpt_fill_pte(gpt_header *gpt_h, gpt_entry *gpt_e, sizeof(gpt_entry_attributes));
/* partition name */ - name_len = sizeof(gpt_e[i].partition_name) + efiname_len = sizeof(gpt_e[i].partition_name) / sizeof(efi_char16_t); - for (k = 0; k < name_len; k++) + dosname_len = sizeof(partitions[i].name); + + memset(gpt_e[i].partition_name, 0, + sizeof(gpt_e[i].partition_name)); + + for (k = 0; k < min(dosname_len, efiname_len); k++) gpt_e[i].partition_name[k] = (efi_char16_t)(partitions[i].name[k]);

On Sun, May 19, 2013 at 12:53:34PM -0000, Marek Vasut wrote:
Make sure to never access beyond bounds of either EFI partition name or DOS partition name. This situation is happening:
part.h: disk_partition_t->name is 32-byte long part_efi.h: gpt_entry->partition_name is 36-bytes long
The loop in part_efi.c copies over 36 bytes and thus accesses beyond the disk_partition_t->name .
Fix this by picking the shortest of source and destination arrays and make sure the destination array is cleared so the trailing bytes are zeroed-out and don't cause issues with string manipulation.
Signed-off-by: Marek Vasut marex@denx.de Cc: Tom Rini trini@ti.com Cc: Simon Glass sjg@chromium.org
Applied to u-boot/master, thanks!
participants (2)
-
Marek Vasut
-
Tom Rini