In the Linux kernel, the following vulnerability has been resolved:
net: netdevsim: dont try to destroy PHC on VFs
PHC gets initialized in nsim_init_netdevsim(), which is only called if (nsim_dev_port_is_pf()).
Create a counterpart of nsim_init_netdevsim() and move the mock_phc_destroy() there.
This fixes a crash trying to destroy netdevsim with VFs instantiated, as caught by running the devlink.sh test:
BUG: kernel NULL pointer dereference, address: 00000000000000b8
RIP: 0010:mock_phc_destroy+0xd/0x30
Call Trace:
<TASK>
nsim_destroy+0x4a/0x70 [netdevsim]
__nsim_dev_port_del+0x47/0x70 [netdevsim]
nsim_dev_reload_destroy+0x105/0x120 [netdevsim]
nsim_drv_remove+0x2f/0xb0 [netdevsim]
device_release_driver_internal+0x1a1/0x210
bus_remove_device+0xd5/0x120
device_del+0x159/0x490
device_unregister+0x12/0x30
del_device_store+0x11a/0x1a0 [netdevsim]
kernfs_fop_write_iter+0x130/0x1d0
vfs_write+0x30b/0x4b0
ksys_write+0x69/0xf0
do_syscall_64+0xcc/0x1e0
entry_SYSCALL_64_after_hwframe+0x6f/0x77
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Linux_kernel | Linux | * | 6.6.14 (excluding) |
| Linux_kernel | Linux | 6.7.0 (including) | 6.7.2 (excluding) |