cve/2024/CVE-2024-38557.md

### [CVE-2024-38557](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-38557)
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### Description

In the Linux kernel, the following vulnerability has been resolved:net/mlx5: Reload only IB representors upon lag disable/enableOn lag disable, the bond IB device along with all of itsrepresentors are destroyed, and then the slaves' representors get reloaded.In case the slave IB representor load fails, the eswitch error flowunloads all representors, including ethernet representors, where thenetdevs get detached and removed from lag bond. Such flow is inaccurateas the lag driver is not responsible for loading/unloading ethernetrepresentors. Furthermore, the flow described above begins by holdinglag lock to prevent bond changes during disable flow. However, whenreaching the ethernet representors detachment from lag, the lag lock isrequired again, triggering the following deadlock:Call trace:__switch_to+0xf4/0x148__schedule+0x2c8/0x7d0schedule+0x50/0xe0schedule_preempt_disabled+0x18/0x28__mutex_lock.isra.13+0x2b8/0x570__mutex_lock_slowpath+0x1c/0x28mutex_lock+0x4c/0x68mlx5_lag_remove_netdev+0x3c/0x1a0 [mlx5_core]mlx5e_uplink_rep_disable+0x70/0xa0 [mlx5_core]mlx5e_detach_netdev+0x6c/0xb0 [mlx5_core]mlx5e_netdev_change_profile+0x44/0x138 [mlx5_core]mlx5e_netdev_attach_nic_profile+0x28/0x38 [mlx5_core]mlx5e_vport_rep_unload+0x184/0x1b8 [mlx5_core]mlx5_esw_offloads_rep_load+0xd8/0xe0 [mlx5_core]mlx5_eswitch_reload_reps+0x74/0xd0 [mlx5_core]mlx5_disable_lag+0x130/0x138 [mlx5_core]mlx5_lag_disable_change+0x6c/0x70 [mlx5_core] // hold ldev->lockmlx5_devlink_eswitch_mode_set+0xc0/0x410 [mlx5_core]devlink_nl_cmd_eswitch_set_doit+0xdc/0x180genl_family_rcv_msg_doit.isra.17+0xe8/0x138genl_rcv_msg+0xe4/0x220netlink_rcv_skb+0x44/0x108genl_rcv+0x40/0x58netlink_unicast+0x198/0x268netlink_sendmsg+0x1d4/0x418sock_sendmsg+0x54/0x60__sys_sendto+0xf4/0x120__arm64_sys_sendto+0x30/0x40el0_svc_common+0x8c/0x120do_el0_svc+0x30/0xa0el0_svc+0x20/0x30el0_sync_handler+0x90/0xb8el0_sync+0x160/0x180Thus, upon lag enable/disable, load and unload only the IB representorsof the slaves preventing the deadlock mentioned above.While at it, refactor the mlx5_esw_offloads_rep_load() function to havea static helper method for its internal logic, in symmetry with therepresentor unload design.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/fkie-cad/nvd-json-data-feeds