Skip to content

fix out-of-bounds read in antlr3UTF16LA backward surrogate peek #240

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
zayeem06 wants to merge 1 commit into
base: master
Choose a base branch
from
Open

fix out-of-bounds read in antlr3UTF16LA backward surrogate peek #240

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
18 changes: 12 additions & 6 deletions runtime/C/src/antlr3inputstream.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -934,14 +934,20 @@ antlr3UTF16LA(pANTLR3_INT_STREAM is, ANTLR3_INT32 la)
// If we found a low surrogate then go back one more character if
// the hi surrogate is there
//
if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END)
if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END)
{
ch2 = *(nextChar-1);
if (ch2 >= UNI_SUR_HIGH_START && ch2 <= UNI_SUR_HIGH_END)
// Only peek at the preceding 16 bits if they are still within
// the source buffer, otherwise we would read before input->data
//
if ((pANTLR3_UINT8)(nextChar - 1) >= (pANTLR3_UINT8)input->data)
{
// Yes, there is a high surrogate to match it so decrement one more and point to that
//
nextChar--;
ch2 = *(nextChar-1);
if (ch2 >= UNI_SUR_HIGH_START && ch2 <= UNI_SUR_HIGH_END)
{
// Yes, there is a high surrogate to match it so decrement one more and point to that
//
nextChar--;
}
}
}
}
Expand Down