🟡 ice: Fix PTP NULL pointer dereference during VSI rebuild (Linux Linux)

Description

In the Linux kernel, the following vulnerability has been resolved: ice: Fix PTP NULL pointer dereference during VSI rebuild Fix race condition where PTP periodic work runs while VSI is being rebuilt, accessing NULL vsi->rx_rings. The sequence was: 1. ice_ptp_prepare_for_reset() cancels PTP work 2. ice_ptp_rebuild() immediately queues PTP work 3. VSI rebuild happens AFTER ice_ptp_rebuild() 4. PTP work runs and accesses NULL vsi->rx_rings Fix: Keep PTP work cancelled during rebuild, only queue it after VSI rebuild completes in ice_rebuild(). Added ice_ptp_queue_work() helper function to encapsulate the logic for queuing PTP work, ensuring it's only queued when PTP is supported and the state is ICE_PTP_READY. Error log: [ 121.392544] ice 0000:60:00.1: PTP reset successful [ 121.392692] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 121.392712] #PF: supervisor read access in kernel mode [ 121.392720] #PF: error_code(0x0000) - not-present page [ 121.392727] PGD 0 [ 121.392734] Oops: Oops: 0000 [#1] SMP NOPTI [ 121.392746] CPU: 8 UID: 0 PID: 1005 Comm: ice-ptp-0000:60 Tainted: G S 6.19.0-rc6+ #4 PREEMPT(voluntary) [ 121.392761] Tainted: [S]=CPU_OUT_OF_SPEC [ 121.392773] RIP: 0010:ice_ptp_update_cached_phctime+0xbf/0x150 [ice] [ 121.393042] Call Trace: [ 121.393047] <TASK> [ 121.393055] ice_ptp_periodic_work+0x69/0x180 [ice] [ 121.393202] kthread_worker_fn+0xa2/0x260 [ 121.393216] ? __pfx_ice_ptp_periodic_work+0x10/0x10 [ice] [ 121.393359] ? __pfx_kthread_worker_fn+0x10/0x10 [ 121.393371] kthread+0x10d/0x230 [ 121.393382] ? __pfx_kthread+0x10/0x10 [ 121.393393] ret_from_fork+0x273/0x2b0 [ 121.393407] ? __pfx_kthread+0x10/0x10 [ 121.393417] ret_from_fork_asm+0x1a/0x30 [ 121.393432] </TASK>