Description
In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Fix deadlock between devlink lock and esw->wq esw->work_queue executes esw_functions_changed_event_handler -> esw_vfs_changed_event_handler and acquires the devlink lock. .eswitch_mode_set (acquires devlink lock in devlink_nl_pre_doit) -> mlx5_devlink_eswitch_mode_set -> mlx5_eswitch_disable_locked -> mlx5_eswitch_event_handler_unregister -> flush_workqueue deadlocks when esw_vfs_changed_event_handler executes. Fix that by no longer flushing the work to avoid the deadlock, and using a generation counter to keep track of work relevance. This avoids an old handler manipulating an esw that has undergone one or more mode changes: - the counter is incremented in mlx5_eswitch_event_handler_unregister. - the counter is read and passed to the ephemeral mlx5_host_work struct. - the work handler takes the devlink lock and bails out if the current generation is different than the one it was scheduled to operate on. - mlx5_eswitch_cleanup does the final draining before destroying the wq. No longer flushing the workqueue has the side effect of maybe no longer cancelling pending vport_change_handler work items, but that's ok since those are disabled elsewhere: - mlx5_eswitch_disable_locked disables the vport eq notifier. - mlx5_esw_vport_disable disarms the HW EQ notification and marks vport->enabled under state_lock to false to prevent pending vport handler from doing anything. - mlx5_eswitch_cleanup destroys the workqueue and makes sure all events are disabled/finished.
Product status
f1bc646c9a06f09aad5d8bacb87103b5573ee45e (git) before 0de867f6e34eae6907b367fd152c55e61cb98608
f1bc646c9a06f09aad5d8bacb87103b5573ee45e (git) before 957d2a58f7f8ebcbdd0a85935e0d2675134b890d
f1bc646c9a06f09aad5d8bacb87103b5573ee45e (git) before 3c7313cb41b1b427078440364d2f042c276a1c0b
f1bc646c9a06f09aad5d8bacb87103b5573ee45e (git) before 4a7838bebc38374f74baaf88bf2cf8d439a92923
f1bc646c9a06f09aad5d8bacb87103b5573ee45e (git) before 90e7e5d14d0bd25ffd019a3aa39d9f1c05fedbe1
f1bc646c9a06f09aad5d8bacb87103b5573ee45e (git) before aed763abf0e905b4b8d747d1ba9e172961572f57
6.0
Any version before 6.0
6.1.167 (semver)
6.6.130 (semver)
6.12.78 (semver)
6.18.19 (semver)
6.19.9 (semver)
7.0 (original_commit_for_fix)
References
git.kernel.org/...c/0de867f6e34eae6907b367fd152c55e61cb98608
git.kernel.org/...c/957d2a58f7f8ebcbdd0a85935e0d2675134b890d
git.kernel.org/...c/3c7313cb41b1b427078440364d2f042c276a1c0b
git.kernel.org/...c/4a7838bebc38374f74baaf88bf2cf8d439a92923
git.kernel.org/...c/90e7e5d14d0bd25ffd019a3aa39d9f1c05fedbe1
git.kernel.org/...c/aed763abf0e905b4b8d747d1ba9e172961572f57