diff options
| author | Elliott Hughes <enh@google.com> | 2018-03-07 13:32:58 -0800 |
|---|---|---|
| committer | Elliott Hughes <enh@google.com> | 2018-03-07 13:32:58 -0800 |
| commit | 41398d03b7e8e0dfb951660ae713e682e9fc0336 (patch) | |
| tree | 802d6cf0350264fffe41021f70dbd8fe1d7c35d4 /libc/stdio/vfprintf.cpp | |
| parent | 0a8d5f3eb8f4087b307f237943a19ae36b094ced (diff) | |
Call __fortify_fatal if printf sees %n.
We've ignored %n for a long time, but that's dangerous too because it
makes it unclear whether the corresponding pointer argument should be
supplied or not.
Remove the ambiguity by just rejecting %n outright.
Bug: http://b/31832608
Test: ran tests
Change-Id: Ic046ad3436a30c6f8f580ea738bdcaeb01c858f8
Diffstat (limited to 'libc/stdio/vfprintf.cpp')
| -rw-r--r-- | libc/stdio/vfprintf.cpp | 20 |
1 files changed, 1 insertions, 19 deletions
diff --git a/libc/stdio/vfprintf.cpp b/libc/stdio/vfprintf.cpp index 91828801d..17e4372cd 100644 --- a/libc/stdio/vfprintf.cpp +++ b/libc/stdio/vfprintf.cpp @@ -449,26 +449,8 @@ int FUNCTION_NAME(FILE* fp, const CHAR_TYPE* fmt0, va_list ap) { lead = expt; } break; -#ifndef NO_PRINTF_PERCENT_N case 'n': - if (flags & LLONGINT) - *GETARG(long long*) = ret; - else if (flags & LONGINT) - *GETARG(long*) = ret; - else if (flags & SHORTINT) - *GETARG(short*) = ret; - else if (flags & CHARINT) - *GETARG(signed char*) = ret; - else if (flags & PTRINT) - *GETARG(ptrdiff_t*) = ret; - else if (flags & SIZEINT) - *GETARG(ssize_t*) = ret; - else if (flags & MAXINT) - *GETARG(intmax_t*) = ret; - else - *GETARG(int*) = ret; - continue; /* no output */ -#endif /* NO_PRINTF_PERCENT_N */ + __fortify_fatal("%%n not allowed on Android"); case 'O': flags |= LONGINT; /*FALLTHROUGH*/ |