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Subject[PATCH 3/3] efi/libstub: Handle unterminated cmdline
Date
Make the command line parsing more robust, by handling the case it is
not NUL-terminated.

Use strnlen instead of strlen, and make sure that the temporary copy is
NUL-terminated before parsing.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
drivers/firmware/efi/libstub/efi-stub-helper.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index f53652a3a106..fe5103086e27 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -194,12 +194,14 @@ efi_status_t efi_parse_options(char const *cmdline)
if (!cmdline)
return EFI_SUCCESS;

- len = strlen(cmdline) + 1;
+ len = strnlen(cmdline, COMMAND_LINE_SIZE-1) + 1;
status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, len, (void **)&buf);
if (status != EFI_SUCCESS)
return status;

- str = skip_spaces(memcpy(buf, cmdline, len));
+ memcpy(buf, cmdline, len-1);
+ buf[len-1] = '\0';
+ str = skip_spaces(buf);

while (*str) {
char *param, *val;
--
2.26.2
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