proxmox-mirrors/efi-boot-shim
1
0
Fork 0
mirror of https://git.proxmox.com/git/efi-boot-shim synced 2025-08-03 08:26:21 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

fallback: handle buffer allocations for fh->GetInfo() prettier.

Browse Source 
At all the places we use fh->GetInfo, covscan can't tell that
fh->GetInfo() will return EFI_BUFFER_TOO_SMALL and we'll allocate on the
first try.

If we just explicitly check for "buffer == NULL" as well, covscan
believes we're doing work we don't need to (which is true!)

So instead, put an rc test to return error for everything else there, so
the allocation isn't in a conditional.

Yet another stupid one, but it's easier to nerf it this way than write
the false-positive rule, and it also hardens against incorrect UEFI
implementations (though we've not seen any yet with the problem this
avoids).

Signed-off-by: Peter Jones <pjones@redhat.com>
This commit is contained in:
Peter Jones 2017-09-27 13:05:16 -04:00 committed by Peter Jones
parent 933bb4f776
commit 05458d227f
1 changed files with 28 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
fallback.c
View File

@ -102,18 +102,20 @@ get_file_size(EFI_FILE_HANDLE fh, UINTN *retsize)
/* The API here is "Call it once with bs=0, it fills in bs,
* then allocate a buffer and ask again to get it filled. */
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &EFI_FILE_INFO_GUID, &bs, NULL);
if (rc == EFI_BUFFER_TOO_SMALL) {
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &EFI_FILE_INFO_GUID,
&bs, buffer);
if (EFI_ERROR(rc) && rc != EFI_BUFFER_TOO_SMALL)
return rc;
if (bs == 0)
return EFI_SUCCESS;
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &EFI_FILE_INFO_GUID, &bs, buffer);
/* This checks *either* the error from the first GetInfo, if it isn't
* the EFI_BUFFER_TOO_SMALL we're expecting, or the second GetInfo call
* in *any* case. */
* the EFI_BUFFER_TOO_SMALL we're expecting, or the second GetInfo
* call in *any* case. */
if (EFI_ERROR(rc)) {
Print(L"Could not get file info: %d\n", rc);
if (buffer)
@ -141,6 +143,8 @@ read_file(EFI_FILE_HANDLE fh, CHAR16 *fullpath, CHAR16 **buffer, UINT64 *bs)
CHAR16 *b = NULL;
rc = get_file_size(fh2, &len);
if (EFI_ERROR(rc)) {
Print(L"Could not get file size for \"%s\": %r\n",
fullpath, rc);
uefi_call_wrapper(fh2->Close, 1, fh2);
return rc;
}
@ -682,15 +686,21 @@ find_boot_csv(EFI_FILE_HANDLE fh, CHAR16 *dirname)
/* The API here is "Call it once with bs=0, it fills in bs,
* then allocate a buffer and ask again to get it filled. */
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &EFI_FILE_INFO_GUID, &bs, NULL);
if (rc == EFI_BUFFER_TOO_SMALL) {
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &EFI_FILE_INFO_GUID,
&bs, buffer);
if (EFI_ERROR(rc) && rc != EFI_BUFFER_TOO_SMALL) {
Print(L"Could not get directory info for \\EFI\\%s\\: %r\n",
dirname, rc);
return rc;
}
if (bs == 0)
return EFI_SUCCESS;
buffer = AllocateZeroPool(bs);
if (!buffer) {
Print(L"Could not allocate memory\n");
return EFI_OUT_OF_RESOURCES;
}
rc = uefi_call_wrapper(fh->GetInfo, 4, fh, &EFI_FILE_INFO_GUID, &bs, buffer);
/* This checks *either* the error from the first GetInfo, if it isn't
* the EFI_BUFFER_TOO_SMALL we're expecting, or the second GetInfo call
* in *any* case. */