Skip to content

Fix QoiDecoder crash on truncated QOI files #9813

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
abhi-0203 wants to merge 1 commit into
base: main
Choose a base branch
from
+18 −3
Open

Fix QoiDecoder crash on truncated QOI files #9813

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
21 changes: 18 additions & 3 deletions src/PIL/QoiImagePlugin.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -61,12 +61,23 @@ def decode(self, buffer: Image.DecoderInput) -> tuple[int, int]:
bands = Image.getmodebands(self.mode)
dest_length = self.state.xsize * self.state.ysize * bands
while len(data) < dest_length:
byte = self.fd.read(1)[0]
byte_data = self.fd.read(1)
if not byte_data:
msg = "image file is truncated"
raise OSError(msg)
byte = byte_data[0]
value: bytes | bytearray
if byte == 0b11111110 and self._previous_pixel: # QOI_OP_RGB
value = bytearray(self.fd.read(3)) + self._previous_pixel[3:]
rgb_data = self.fd.read(3)
if len(rgb_data) < 3:
msg = "image file is truncated"
raise OSError(msg)
value = bytearray(rgb_data) + self._previous_pixel[3:]
elif byte == 0b11111111: # QOI_OP_RGBA
value = self.fd.read(4)
if len(value) < 4:
msg = "image file is truncated"
raise OSError(msg)
else:
op = byte >> 6
if op == 0: # QOI_OP_INDEX
Expand All @@ -86,7 +97,11 @@ def decode(self, buffer: Image.DecoderInput) -> tuple[int, int]:
)
)
elif op == 2 and self._previous_pixel: # QOI_OP_LUMA
second_byte = self.fd.read(1)[0]
second_byte_data = self.fd.read(1)
if not second_byte_data:
msg = "image file is truncated"
raise OSError(msg)
second_byte = second_byte_data[0]
diff_green = (byte & 0b00111111) - 32
diff_red = ((second_byte & 0b11110000) >> 4) - 8
diff_blue = (second_byte & 0b00001111) - 8
Expand Down
Loading