Entreprise française de cybersécurité depuis 2004
☎ 03 60 47 09 81 - info@securiteinfo.com
☎ 03 60 47 09 81 - info@securiteinfo.com
In the Linux kernel, the following vulnerability has been resolved:tmpfs: fix race on handling dquot rbtreeA syzkaller reproducer found a race while attempting to remove dquotinformation from the rb tree.Fetching the rb_tree root node must also be protected by thedqopt->dqio_sem, otherwise, giving the right timing, shmem_release_dquot()will trigger a warning because it couldn't find a node in the tree, whenthe real reason was the root node changing before the search starts:Thread 1 Thread 2- shmem_release_dquot() - shmem_{acquire,release}_dquot()- fetch ROOT - Fetch ROOT - acquire dqio_sem- wait dqio_sem - do something, triger a tree rebalance - release dqio_sem- acquire dqio_sem- start searching for the node, but from the wrong location, missing the node, and triggering a warning.
No PoCs from references.
- https://github.com/fkie-cad/nvd-json-data-feeds