| Message ID | 20181104233426.24961-1-agraf@suse.de |
|---|---|
| State | Accepted |
| Commit | c2e1ad70a75048d802bf5c3296a043761939dae6 |
| Headers | show |
| Series | efi_loader: Ensure memory allocations are page aligned | expand |
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c index 5bd4f4d7fc..1ffcf92eb2 100644 --- a/lib/efi_loader/efi_memory.c +++ b/lib/efi_loader/efi_memory.c @@ -294,6 +294,12 @@ static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr) { struct list_head *lhandle; + /* + * Prealign input max address, so we simplify our matching + * logic below and can just reuse it as return pointer. + */ + max_addr &= ~EFI_PAGE_MASK; + list_for_each(lhandle, &efi_mem) { struct efi_mem_list *lmem = list_entry(lhandle, struct efi_mem_list, link);
When the max_addr parameter of efi_find_free_memory() is within bounds of an existing map and fits the reservation, we just return that address as allocation value. That breaks however if max_addr is not page aligned. So ensure that it always comes to us page aligned, simplifying the allocation logic. Without this, I've seen breakage where we were allocating pages at -1U (32bit) which fits into a region that spans beyond 0x100000000. In that case, we would return 0xffffffff as a valid memory allocation, although we usually do guarantee they are all page aligned. Fix this by aligning the max address argument always. Signed-off-by: Alexander Graf <agraf@suse.de> --- lib/efi_loader/efi_memory.c | 6 ++++++ 1 file changed, 6 insertions(+)