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.
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |