diff mbox series

efi/libstub: Fix path separator regression

Message ID 20200615115109.7823-1-fent@in.tum.de
State New
Headers show
Series efi/libstub: Fix path separator regression | expand

Commit Message

Philipp Fent June 15, 2020, 11:51 a.m. UTC 
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@in.tum.de>
---
 drivers/firmware/efi/libstub/file.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

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';