diff options
| author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-07-28 18:57:22 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-07-31 11:08:17 +0200 |
| commit | f49236ae424d499d02ee3ce35fb9130ddf95b03f (patch) | |
| tree | b29fb9cddefee778da2e4494edf3d846e89e775a | |
| parent | 0eb1a8af01d6264cf948d67c8bff15e2eb859355 (diff) | |
x86/kaslr: Add a check that the random address is in range
Check in find_random_phys_addr() that the chosen address is inside the
range that was required.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200728225722.67457-22-nivedita@alum.mit.edu
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 80cdd2071305..735fcb2a8b7b 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -803,6 +803,8 @@ static void process_e820_entries(unsigned long minimum, static unsigned long find_random_phys_addr(unsigned long minimum, unsigned long image_size) { + u64 phys_addr; + /* Bail out early if it's impossible to succeed. */ if (minimum + image_size > mem_limit) return 0; @@ -816,7 +818,15 @@ static unsigned long find_random_phys_addr(unsigned long minimum, if (!process_efi_entries(minimum, image_size)) process_e820_entries(minimum, image_size); - return slots_fetch_random(); + phys_addr = slots_fetch_random(); + + /* Perform a final check to make sure the address is in range. */ + if (phys_addr < minimum || phys_addr + image_size > mem_limit) { + warn("Invalid physical address chosen!\n"); + return 0; + } + + return (unsigned long)phys_addr; } static unsigned long find_random_virt_addr(unsigned long minimum, |