2020-08-13 18:59:18

by Arvind Sankar

[permalink] [raw]
Subject: [PATCH 3/3] efi/libstub: Handle unterminated cmdline

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 <[email protected]>
---
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


Subject: [tip: efi/urgent] efi/libstub: Handle unterminated cmdline

The following commit has been merged into the efi/urgent branch of tip:

Commit-ID: 8a8a3237a78cbc0557f0eb16a89f16d616323e99
Gitweb: https://git.kernel.org/tip/8a8a3237a78cbc0557f0eb16a89f16d616323e99
Author: Arvind Sankar <[email protected]>
AuthorDate: Thu, 13 Aug 2020 14:58:11 -04:00
Committer: Ard Biesheuvel <[email protected]>
CommitterDate: Thu, 20 Aug 2020 11:18:58 +02:00

efi/libstub: Handle unterminated cmdline

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.

Cc: <[email protected]>
Signed-off-by: Arvind Sankar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ard Biesheuvel <[email protected]>
---
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 f53652a..f735db5 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;