diff options
| author | Peter Mitsis <peter.mitsis@windriver.com> | 2016-03-18 10:48:02 -0400 |
|---|---|---|
| committer | Gerrit Code Review <gerrit@zephyrproject.org> | 2016-03-19 11:03:54 +0000 |
| commit | 7f14e706ec41fa525612b9519277429652bbaab9 (patch) | |
| tree | f20d54a7b217261e570a81d5157a4ce12644ad66 /lib | |
| parent | de5dd2f0ffe5ba934650c7526126028c4be247ed (diff) | |
printf: Limit width modifier to [0..MAXFLD]
When capping the the absolute value of the width modifier in printf(),
it must first be cast to an 'unsigned'. This stems from the fact that
in two's complement, not all negative numbers have a positive counterpart.
Change-Id: I3e6f92f68ab1b8dab48bbf883c5ad4b078a93f87
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libc/minimal/source/stdout/prf.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/lib/libc/minimal/source/stdout/prf.c b/lib/libc/minimal/source/stdout/prf.c index 58ca7f0dd..6e6d829c1 100644 --- a/lib/libc/minimal/source/stdout/prf.c +++ b/lib/libc/minimal/source/stdout/prf.c @@ -586,8 +586,15 @@ int _prf(int (*func)(), void *dest, char *format, va_list vargs) c = *format++; } - if (width > MAXFLD) + /* + * If <width> is INT_MIN, then its absolute value can + * not be expressed as a positive number using 32-bit + * two's complement. To cover that case, cast it to + * an unsigned before comparing it against MAXFLD. + */ + if ((unsigned) width > MAXFLD) { width = MAXFLD; + } if (c == '.') { c = *format++; |