GHSA-fwj8-62r8-8p8m

Описание

Summary

Missing error handling could lead an authenticated Incus user to cause a daemon crash through the import of a truncated storage bucket backup file.

Details

It was found that TransferManager.UploadAllFiles iterates over tar entries but only checks for io.EOF from tr.Next(). When tr.Next() returns a non-EOF error, such as unexpected EOF from a truncated archive, the header hdr is nil and the code continues to access hdr.Name, causing a nil-pointer dereference that panics the daemon.

This may allow the Incus daemon to be crashed during S3 bucket restore if a truncated or corrupted backup archive is provided. A panic can occur when a malformed archive produces a non-EOF tar read error after the first entry. Any caller of UploadAllFiles that processes attacker-controlled archive content may be affected.

Affected File: https://github.com/lxc/incus/blob/v6.22.0/…server/storage/s3/transfer_manager.go#L127

The tar-iteration loop only checks for EOF:

Affected Code:

When tr.Next() returns a non-EOF error, hdr is nil. The code does not check for this case and immediately dereferences hdr.Name.

This was confirmed as follows:

Command:

Output:

It is recommended to add a non-EOF error check after tr.Next().

Proposed Fix:

A patch is available at https://github.com/lxc/incus/releases/tag/v7.0.0.

Credits

This issue was discovered and reported by the team at 7asecurity (https://7asecurity.com/)