devlink: hold region lock when flushing snapshots

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: devlink: hold region lock when flushing snapshots Netdevsim triggers a splat on reload, when it destroys regions with snapshots pending: WARNING: CPU: 1 PID: 787 at net/core/devlink.c:6291 devlink_region_snapshot_del+0x12e/0x140 CPU: 1 PID: 787 Comm: devlink Not tainted 6.1.0-07460-g7ae9888d6e1c #580 RIP: 0010:devlink_region_snapshot_del+0x12e/0x140 Call Trace: <TASK> devl_region_destroy+0x70/0x140 nsim_dev_reload_down+0x2f/0x60 [netdevsim] devlink_reload+0x1f7/0x360 devlink_nl_cmd_reload+0x6ce/0x860 genl_family_rcv_msg_doit.isra.0+0x145/0x1c0 This is the locking assert in devlink_region_snapshot_del(), we're supposed to be holding the region->snapshot_lock here.

References

• https://git.kernel.org/stable/c/49383d4e59bb704341aaa1d51440ccce58270e61
• https://git.kernel.org/stable/c/6298cab4d80bfdb6fe01fe31fd9f0ba26317fdae
• https://git.kernel.org/stable/c/b4cafb3d2c740f8d1b1234b43ac4a60e5291c960