Merge pull request #408 from epage/key

fix(parser): Avoid stackoverflow with long dotted keys
toml-rs · Dec 28, 2022 · ce27cd7 · ce27cd7
2 parents 9174af0 + b084184
commit ce27cd7
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Showing 2 changed files with 18 additions and 0 deletions.
diff --git a/crates/toml_edit/src/parser/key.rs b/crates/toml_edit/src/parser/key.rs
@@ -6,6 +6,7 @@ use nom8::combinator::peek;
 use nom8::multi::separated_list1;
 
 use crate::key::Key;
+use crate::parser::errors::CustomError;
 use crate::parser::prelude::*;
 use crate::parser::strings::{basic_string, literal_string};
 use crate::parser::trivia::{from_utf8_unchecked, ws};
@@ -24,6 +25,11 @@ pub(crate) fn key(input: Input<'_>) -> IResult<Input<'_>, Vec<Key>, ParserError<
         }),
     )
     .context(Context::Expression("key"))
+    .map_res(|k| {
+        // Inserting the key will require recursion down the line
+        RecursionCheck::check_depth(k.len())?;
+        Ok::<_, CustomError>(k)
+    })
     .parse(input)
 }
 

diff --git a/crates/toml_edit/src/parser/mod.rs b/crates/toml_edit/src/parser/mod.rs
@@ -70,6 +70,14 @@ pub(crate) mod prelude {
 
     #[cfg(not(feature = "unbounded"))]
     impl RecursionCheck {
+        pub(crate) fn check_depth(depth: usize) -> Result<(), super::errors::CustomError> {
+            if depth < 128 {
+                Ok(())
+            } else {
+                Err(super::errors::CustomError::RecursionLimitExceeded)
+            }
+        }
+
         pub(crate) fn recursing(
             mut self,
             input: Input<'_>,
@@ -95,6 +103,10 @@ pub(crate) mod prelude {
 
     #[cfg(feature = "unbounded")]
     impl RecursionCheck {
+        pub(crate) fn check_depth(_depth: usize) -> Result<(), super::errors::CustomError> {
+            Ok(())
+        }
+
         pub(crate) fn recursing(
             self,
             _input: Input<'_>,