diff options
| author | Richard J. Moore <rich@kde.org> | 2015-02-24 19:02:35 +0000 |
|---|---|---|
| committer | Richard J. Moore <rich@kde.org> | 2015-02-26 22:32:51 +0000 |
| commit | e50aa2252cdd5cb53eef7d8c4503c7edff634f68 (patch) | |
| tree | 78a27cca224e7cf78fca698548a326343497630c | |
| parent | 7296f653afe717118fc8533f0a72e3fb77fc42d8 (diff) | |
Fix a division by zero when processing malformed BMP files.
This fixes a division by 0 when processing a maliciously crafted BMP
file. No impact beyond DoS.
Backport of 661f6bfd032dacc62841037732816a583640e187
Task-number: QTBUG-44547
Change-Id: I43f06e752b11cb50669101460902a82b885ae618
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
| -rw-r--r-- | src/gui/image/qbmphandler.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/gui/image/qbmphandler.cpp b/src/gui/image/qbmphandler.cpp index b22e842202..30fa9e0c28 100644 --- a/src/gui/image/qbmphandler.cpp +++ b/src/gui/image/qbmphandler.cpp @@ -319,10 +319,16 @@ static bool read_dib_body(QDataStream &s, const BMP_INFOHDR &bi, int offset, int } } else if (comp == BMP_BITFIELDS && (nbits == 16 || nbits == 32)) { red_shift = calc_shift(red_mask); + if (((red_mask >> red_shift) + 1) == 0) + return false; red_scale = 256 / ((red_mask >> red_shift) + 1); green_shift = calc_shift(green_mask); + if (((green_mask >> green_shift) + 1) == 0) + return false; green_scale = 256 / ((green_mask >> green_shift) + 1); blue_shift = calc_shift(blue_mask); + if (((blue_mask >> blue_shift) + 1) == 0) + return false; blue_scale = 256 / ((blue_mask >> blue_shift) + 1); } else if (comp == BMP_RGB && (nbits == 24 || nbits == 32)) { blue_mask = 0x000000ff; |