feat(git): add size limits for git operations

- Added MAX_CHERRY_PICK_PATCH_BYTES limit of 100MB for cherry-pick operations
- Added MAX_ACTION_CONTENT_BYTES limit of 100MB for commit action content
- Added MAX_COMMIT_MESSAGE_BYTES limit of 10MB for commit messages
- Added MAX_CHECK_REVISIONS limit of 10,000 for revision checks
- Added MAX_REBASE_COMMITS limit of 10,000 for rebase operations
- Added MAX_REBASE_PATCH_BYTES limit of 100MB for rebase patches
- Added MAX_RESOLUTION_CONTENT_BYTES limit of 100MB for merge conflict resolutions
- Added MAX_REVERT_PATCH_BYTES limit of 100MB for revert operations
- Return InvalidArgument error when size limits are exceeded with descriptive messages

commit/cherry_pick_commit.rs

@@ -3,6 +3,8 @@ use crate::commit::create_commit::command_ok;
 use crate::error::{GitError, GitResult};
 use crate::pb::{CherryPickCommitRequest, CreateCommitResponse, GetCommitRequest};
 
+const MAX_CHERRY_PICK_PATCH_BYTES: usize = 100 * 1024 * 1024;
+
 impl GitBare {
     pub fn cherry_pick_commit(
         &self,
@@ -77,6 +79,12 @@ impl GitBare {
             .unchecked()
             .run()?;
         let patch_data = command_ok(diff)?;
+        if patch_data.len() > MAX_CHERRY_PICK_PATCH_BYTES {
+            return Err(GitError::InvalidArgument(format!(
+                "cherry-pick patch too large ({} bytes, max {MAX_CHERRY_PICK_PATCH_BYTES})",
+                patch_data.len()
+            )));
+        }
 
         let apply = duct::cmd(
             "git",

commit/create_commit.rs

@@ -23,6 +23,14 @@ impl GitBare {
             }
         }
 
+        const MAX_ACTIONS_PER_COMMIT: usize = 10_000;
+        if request.actions.len() > MAX_ACTIONS_PER_COMMIT {
+            return Err(GitError::InvalidArgument(format!(
+                "too many commit actions ({} > max {MAX_ACTIONS_PER_COMMIT})",
+                request.actions.len()
+            )));
+        }
+
         let repo = self.gix_repo()?;
         let branch = request.branch.clone();
         tracing::debug!(
@@ -160,6 +168,14 @@ impl GitBare {
         index_path: &str,
         action: &crate::pb::CreateCommitAction,
     ) -> GitResult<()> {
+        const MAX_ACTION_CONTENT_BYTES: usize = 100 * 1024 * 1024;
+        if action.content.len() > MAX_ACTION_CONTENT_BYTES {
+            return Err(GitError::InvalidArgument(format!(
+                "action content too large ({} bytes, max {MAX_ACTION_CONTENT_BYTES})",
+                action.content.len()
+            )));
+        }
+
         // Validate file paths to prevent command injection / traversal
         if !action.file_path.is_empty() {
             crate::sanitize::validate_file_path(&action.file_path)?;
@@ -325,6 +341,14 @@ impl GitBare {
         author: Option<&crate::pb::Signature>,
         committer: Option<&crate::pb::Signature>,
     ) -> GitResult<String> {
+        const MAX_COMMIT_MESSAGE_BYTES: usize = 10 * 1024 * 1024;
+        if message.len() > MAX_COMMIT_MESSAGE_BYTES {
+            return Err(GitError::InvalidArgument(format!(
+                "commit message too large ({} bytes, max {MAX_COMMIT_MESSAGE_BYTES})",
+                message.len()
+            )));
+        }
+
         let mut args = vec![
             "--git-dir".to_string(),
             self.bare_dir.to_string_lossy().into_owned(),

commit/query.rs

@@ -83,6 +83,13 @@ impl GitBare {
         &self,
         request: CheckObjectsExistRequest,
     ) -> GitResult<CheckObjectsExistResponse> {
+        const MAX_CHECK_REVISIONS: usize = 10_000;
+        if request.revisions.len() > MAX_CHECK_REVISIONS {
+            return Err(crate::error::GitError::InvalidArgument(format!(
+                "too many revisions (max {MAX_CHECK_REVISIONS})"
+            )));
+        }
+
         let repo = self.gix_repo()?;
         let mut revisions = Vec::new();
 

commit/revert_commit.rs

@@ -3,6 +3,8 @@ use crate::commit::create_commit::command_ok;
 use crate::error::{GitError, GitResult};
 use crate::pb::{CreateCommitResponse, GetCommitRequest, RevertCommitRequest};
 
+const MAX_REVERT_PATCH_BYTES: usize = 100 * 1024 * 1024;
+
 impl GitBare {
     pub fn revert_commit(&self, request: RevertCommitRequest) -> GitResult<CreateCommitResponse> {
         let target_branch = request.branch.clone();
@@ -79,6 +81,12 @@ impl GitBare {
         .unchecked()
         .run()?;
         let patch_data = command_ok(diff)?;
+        if patch_data.len() > MAX_REVERT_PATCH_BYTES {
+            return Err(GitError::InvalidArgument(format!(
+                "revert patch too large ({} bytes, max {MAX_REVERT_PATCH_BYTES})",
+                patch_data.len()
+            )));
+        }
 
         let apply = duct::cmd(
             "git",