| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.8 147/148] efi/libstub: Handle unterminated cmdline | Date | Mon, 24 Aug 2020 10:30:45 +0200 |
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From: Arvind Sankar <nivedita@alum.mit.edu>
commit 8a8a3237a78cbc0557f0eb16a89f16d616323e99 upstream.
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: <stable@vger.kernel.org> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200813185811.554051-4-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/firmware/efi/libstub/efi-stub-helper.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- 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 cons 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;
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