diff options
| author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-05-18 15:07:07 -0400 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2020-05-19 10:32:04 +0200 |
| commit | f97ca2c816748e3b7dee58775632f9e9269071e6 (patch) | |
| tree | 92b2305c2e31b83748f50ca3cee7624d2719223f /drivers/firmware/efi/libstub | |
| parent | 6c4bcd8a46a98856c06ca3ba8a80f03a61e23960 (diff) | |
efi/printf: Abort on invalid format
If we get an invalid conversion specifier, bail out instead of trying to
fix it up. The format string likely has a typo or assumed we support
something that we don't, in either case the remaining arguments won't
match up with the remaining format string.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-16-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'drivers/firmware/efi/libstub')
| -rw-r--r-- | drivers/firmware/efi/libstub/vsprintf.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/firmware/efi/libstub/vsprintf.c b/drivers/firmware/efi/libstub/vsprintf.c index c09d97051c7e..cca6b802b028 100644 --- a/drivers/firmware/efi/libstub/vsprintf.c +++ b/drivers/firmware/efi/libstub/vsprintf.c @@ -359,12 +359,13 @@ int vsprintf(char *buf, const char *fmt, va_list ap) break; default: - *str++ = '%'; - if (*fmt) - *str++ = *fmt; - else - --fmt; - continue; + /* + * Bail out if the conversion specifier is invalid. + * There's probably a typo in the format string and the + * remaining specifiers are unlikely to match up with + * the arguments. + */ + goto fail; } if (*fmt == 'p') { num = (unsigned long)va_arg(args, void *); @@ -434,6 +435,7 @@ output: while (field_width-- > 0) *str++ = ' '; } +fail: *str = '\0'; va_end(args); |