In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrumacltcam: Fix incorrect list API usage
Both the function that migrates all the chunks within a region and the function that migrates all the entries within a chunk call listfirstentry() on the respective lists without checking that the lists are not empty. This is incorrect usage of the API, which leads to the following warning [1].
Fix by returning if the lists are empty as there is nothing to migrate in this case.
[1] WARNING: CPU: 0 PID: 6437 at drivers/net/ethernet/mellanox/mlxsw/spectrumacltcam.c:1266 mlxswspacltcamvchunkmigrateall+0x1f1/0> Modules linked in: CPU: 0 PID: 6437 Comm: kworker/0:37 Not tainted 6.9.0-rc3-custom-00883-g94a65f079ef6 #39 Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019 Workqueue: mlxswcore mlxswspacltcamvregionrehashwork RIP: 0010:mlxswspacltcamvchunkmigrateall+0x1f1/0x2c0 [...] Call Trace: <TASK> mlxswspacltcamvregionrehashwork+0x6c/0x4a0 processonework+0x151/0x370 workerthread+0x2cb/0x3e0 kthread+0xd0/0x100 retfromfork+0x34/0x50 retfromfork_asm+0x1a/0x30 </TASK>