Commit 9302c1bb8e47 ("efi/libstub: Rewrite file I/O routine") introduced a
regression that made a couple of (badly configured) systems fail to
boot [1]: Until 5.6, we silently accepted Unix-style file separators in
EFI paths, which might violate the EFI standard, but are an easy to make
mistake. This fix restores the pre-5.7 behaviour.
[1] https://bbs.archlinux.org/viewtopic.php?id=256273
Signed-off-by: Philipp Fent <fent@xxxxxxxxx>
---
drivers/firmware/efi/libstub/file.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c
index 2005e33b33d5..f8a28a6e0bde 100644
--- a/drivers/firmware/efi/libstub/file.c
+++ b/drivers/firmware/efi/libstub/file.c
@@ -102,11 +102,21 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len,
if (!found)
return 0;
+ /* Skip any leading slashes */
+ while (cmdline[i] == L'/' || cmdline[i] == L'\\')
+ i++;
+
while (--result_len > 0 && i < cmdline_len) {
if (cmdline[i] == L'\0' ||
cmdline[i] == L'\n' ||
cmdline[i] == L' ')
break;
+ /* Replace UNIX dir separators with EFI standard separators */
+ if (cmdline[i] == L'/') {
+ *result++ = L'\\';
+ i++;
+ continue;
+ }
*result++ = cmdline[i++];
}
*result = L'\0';
--
2.27.0
