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| author | Peter Jones <pjones@redhat.com> | 2016-10-17 16:16:17 -0400 |
|---|---|---|
| committer | Peter Jones <pjones@redhat.com> | 2017-02-06 11:16:24 -0500 |
| commit | 03b9f800b99b2f980e13fbc994d14bd8ec340c41 (patch) | |
| tree | 1fbbf350568671b101d0a0da6ad2cae91a8ed9e3 /shim.c | |
| parent | 431d893b41c53f6a022031ca0cc66fd298e0e472 (diff) | |
| download | efi-boot-shim-03b9f800b99b2f980e13fbc994d14bd8ec340c41.tar.gz efi-boot-shim-03b9f800b99b2f980e13fbc994d14bd8ec340c41.zip | |
generate_hash(): make check_size() set an error, and verify SecDir size.
Currently generate_hash() attempts to include any trailing data at the
end of the binary in the resulting digest, but it won't include such
data if the size computed is wrong because context->SecDir->Size is
invalid. In this case the return code is EFI_SUCCESS, and the hash will
match any a binary as if the Attribute Certificate Table and anything
after it are missing. This is wrong.
Signed-off-by: Peter Jones <pjones@redhat.com>
Diffstat (limited to 'shim.c')
| -rw-r--r-- | shim.c | 9 |
1 files changed, 9 insertions, 0 deletions
@@ -686,12 +686,14 @@ static BOOLEAN secure_mode (void) #define check_size_line(data, datasize_in, hashbase, hashsize, l) ({ \ if ((unsigned long)hashbase > \ (unsigned long)data + datasize_in) { \ + status = EFI_INVALID_PARAMETER; \ perror(L"shim.c:%d Invalid hash base 0x%016x\n", l, \ hashbase); \ goto done; \ } \ if ((unsigned long)hashbase + hashsize > \ (unsigned long)data + datasize_in) { \ + status = EFI_INVALID_PARAMETER; \ perror(L"shim.c:%d Invalid hash size 0x%016x\n", l, \ hashsize); \ goto done; \ @@ -887,6 +889,13 @@ static EFI_STATUS generate_hash (char *data, unsigned int datasize_in, if (datasize > SumOfBytesHashed) { hashbase = data + SumOfBytesHashed; hashsize = datasize - context->SecDir->Size - SumOfBytesHashed; + + if ((datasize - SumOfBytesHashed < context->SecDir->Size) || + (SumOfBytesHashed - hashsize != context->SecDir->VirtualAddress)) { + perror(L"Malformed binary after Attribute Certificate Table\n"); + status = EFI_INVALID_PARAMETER; + goto done; + } check_size(data, datasize_in, hashbase, hashsize); if (!(Sha256Update(sha256ctx, hashbase, hashsize)) || |