CVE-2024-27058

In the Linux kernel, the following vulnerability has been resolved: tmpfs:
fix race on handling dquot rbtree A syzkaller reproducer found a race while
attempting to remove dquot information from the rb tree. Fetching the
rb_tree root node must also be protected by the dqopt->dqio_sem, otherwise,
giving the right timing, shmem_release_dquot() will trigger a warning
because it couldn’t find a node in the tree, when the 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.