From: Arvind Sankar <nivedita@alum.mit.edu>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Subject: [PATCH] efi/libstub: Don't parse overlong command lines
Date: Wed, 20 May 2020 20:29:21 -0400 [thread overview]
Message-ID: <20200521002921.69650-1-nivedita@alum.mit.edu> (raw)
In-Reply-To: <CAMj1kXGuM6sEE5HoAmGP7EZDnyUsW73FH+f2C_MvH76UCMYkpg@mail.gmail.com>
Check if the command line passed in is larger than COMMAND_LINE_SIZE,
and truncate it to the last full argument if so.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
.../firmware/efi/libstub/efi-stub-helper.c | 28 +++++++++++++++----
1 file changed, 23 insertions(+), 5 deletions(-)
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 2a6aded4f2a9..89f075275300 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -9,10 +9,12 @@
#include <stdarg.h>
+#include <linux/ctype.h>
#include <linux/efi.h>
#include <linux/kernel.h>
#include <linux/printk.h> /* For CONSOLE_LOGLEVEL_* */
#include <asm/efi.h>
+#include <asm/setup.h>
#include "efistub.h"
@@ -216,22 +218,33 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len)
unsigned long cmdline_addr = 0;
int options_chars = efi_table_attr(image, load_options_size) / 2;
const u16 *options = efi_table_attr(image, load_options);
- int options_bytes = 0; /* UTF-8 bytes */
+ int options_bytes = 0, safe_options_bytes = 0; /* UTF-8 bytes */
+ bool in_quote = false;
efi_status_t status;
if (options) {
s2 = options;
- while (options_chars--) {
+ while (options_bytes < COMMAND_LINE_SIZE && options_chars--) {
u16 c = *s2++;
- if (c == L'\0' || c == L'\n')
- break;
+ if (c < 0x80) {
+ if (c == L'\0' || c == L'\n')
+ break;
+ if (c == L'"')
+ in_quote = !in_quote;
+ else if (!in_quote && isspace((char)c))
+ safe_options_bytes = options_bytes;
+
+ options_bytes++;
+ continue;
+ }
+
/*
* Get the number of UTF-8 bytes corresponding to a
* UTF-16 character.
* The first part handles everything in the BMP.
*/
- options_bytes += 1 + (c >= 0x80) + (c >= 0x800);
+ options_bytes += 2 + (c >= 0x800);
/*
* Add one more byte for valid surrogate pairs. Invalid
* surrogates will be replaced with 0xfffd and take up
@@ -252,6 +265,11 @@ char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len)
}
}
}
+ if (options_bytes >= COMMAND_LINE_SIZE) {
+ options_bytes = safe_options_bytes;
+ efi_err("Command line is too long: truncated to %d bytes\n",
+ options_bytes);
+ }
}
options_bytes++; /* NUL termination */
--
2.26.2
next prev parent reply other threads:[~2020-05-21 0:29 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-18 19:06 [PATCH 00/24] efi/libstub: Add printf implementation Arvind Sankar
2020-05-18 19:06 ` [PATCH 01/24] efi/libstub: Include dependencies of efistub.h Arvind Sankar
2020-05-18 19:06 ` [PATCH 02/24] efi/libstub: Rename efi_[char16_]printk to efi_[char16_]puts Arvind Sankar
2020-05-18 19:06 ` [PATCH 03/24] efi/libstub: Buffer output of efi_puts Arvind Sankar
2020-05-18 19:06 ` [PATCH 04/24] efi/libstub: Add a basic printf implementation Arvind Sankar
2020-05-18 19:06 ` [PATCH 05/24] efi/libstub: Optimize for size instead of speed Arvind Sankar
2020-06-05 0:31 ` Andrey Ignatov
2020-06-05 6:33 ` Ard Biesheuvel
2020-06-05 13:14 ` Arvind Sankar
2020-06-05 13:32 ` Arvind Sankar
2020-06-05 14:53 ` Ard Biesheuvel
2020-06-05 15:10 ` Arvind Sankar
2020-06-05 15:11 ` Ard Biesheuvel
2020-06-05 15:06 ` [PATCH] efi/x86: Fix build with gcc 4 Arvind Sankar
2020-06-05 16:09 ` Andrey Ignatov
2020-06-15 9:43 ` Ard Biesheuvel
2020-05-18 19:06 ` [PATCH 06/24] efi/printf: Drop %n format and L qualifier Arvind Sankar
2020-05-18 19:06 ` [PATCH 07/24] efi/printf: Add 64-bit and 8-bit integer support Arvind Sankar
2020-05-18 19:07 ` [PATCH 08/24] efi/printf: Factor out flags parsing and handle '%' earlier Arvind Sankar
2020-05-18 19:07 ` [PATCH 09/24] efi/printf: Fix minor bug in precision handling Arvind Sankar
2020-05-18 19:07 ` [PATCH 10/24] efi/printf: Merge 'p' with the integer formats Arvind Sankar
2020-05-18 19:07 ` [PATCH 11/24] efi/printf: Factor out width/precision parsing Arvind Sankar
2020-05-18 19:07 ` [PATCH 12/24] efi/printf: Factor out integer argument retrieval Arvind Sankar
2020-05-18 19:07 ` [PATCH 13/24] efi/printf: Handle null string input Arvind Sankar
2020-05-18 19:07 ` [PATCH 14/24] efi/printf: Refactor code to consolidate padding and output Arvind Sankar
2020-05-18 19:07 ` [PATCH 15/24] efi/printf: Abort on invalid format Arvind Sankar
2020-05-18 19:07 ` [PATCH 16/24] efi/printf: Turn vsprintf into vsnprintf Arvind Sankar
2020-05-18 19:07 ` [PATCH 17/24] efi/libstub: Implement printk-style logging Arvind Sankar
2020-05-19 8:22 ` Ard Biesheuvel
2020-05-19 15:07 ` Arvind Sankar
2020-05-20 16:38 ` Arvind Sankar
2020-05-20 16:38 ` Ard Biesheuvel
2020-05-20 17:02 ` Arvind Sankar
2020-05-20 17:09 ` Ard Biesheuvel
2020-05-18 19:07 ` [PATCH 18/24] efi/libstub: Add definitions for console input and events Arvind Sankar
2020-05-18 19:07 ` [PATCH 19/24] efi/gop: Add an option to list out the available GOP modes Arvind Sankar
2020-05-18 19:07 ` [PATCH 20/24] efi/printf: Add support for wchar_t (UTF-16) Arvind Sankar
2020-05-18 19:07 ` [PATCH 21/24] efi/libstub: Add UTF-8 decoding to efi_puts Arvind Sankar
2020-05-18 19:07 ` [PATCH 22/24] efi/libstub: Use %ls for filename Arvind Sankar
2020-05-18 19:07 ` [PATCH 23/24] efi/libstub: Get the exact UTF-8 length Arvind Sankar
2020-05-18 19:07 ` [PATCH 24/24] efi/libstub: Use snprintf with %ls to convert the command line Arvind Sankar
2020-05-19 7:53 ` [PATCH 00/24] efi/libstub: Add printf implementation Ard Biesheuvel
2020-05-19 15:06 ` Arvind Sankar
2020-05-19 16:44 ` Ard Biesheuvel
2020-05-21 0:29 ` Arvind Sankar [this message]
2020-05-22 13:13 ` [PATCH] efi/libstub: Don't parse overlong command lines Ard Biesheuvel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200521002921.69650-1-nivedita@alum.mit.edu \
--to=nivedita@alum.mit.edu \
--cc=ardb@kernel.org \
--cc=linux-efi@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).