| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47449: ice: fix locking for Tx timestamp tracking flush |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| ice: fix locking for Tx timestamp tracking flush |
| |
| Commit 4dd0d5c33c3e ("ice: add lock around Tx timestamp tracker flush") |
| added a lock around the Tx timestamp tracker flow which is used to |
| cleanup any left over SKBs and prepare for device removal. |
| |
| This lock is problematic because it is being held around a call to |
| ice_clear_phy_tstamp. The clear function takes a mutex to send a PHY |
| write command to firmware. This could lead to a deadlock if the mutex |
| actually sleeps, and causes the following warning on a kernel with |
| preemption debugging enabled: |
| |
| [ 715.419426] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:573 |
| [ 715.427900] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 3100, name: rmmod |
| [ 715.435652] INFO: lockdep is turned off. |
| [ 715.439591] Preemption disabled at: |
| [ 715.439594] [<0000000000000000>] 0x0 |
| [ 715.446678] CPU: 52 PID: 3100 Comm: rmmod Tainted: G W OE 5.15.0-rc4+ #42 bdd7ec3018e725f159ca0d372ce8c2c0e784891c |
| [ 715.458058] Hardware name: Intel Corporation S2600STQ/S2600STQ, BIOS SE5C620.86B.02.01.0010.010620200716 01/06/2020 |
| [ 715.468483] Call Trace: |
| [ 715.470940] dump_stack_lvl+0x6a/0x9a |
| [ 715.474613] ___might_sleep.cold+0x224/0x26a |
| [ 715.478895] __mutex_lock+0xb3/0x1440 |
| [ 715.482569] ? stack_depot_save+0x378/0x500 |
| [ 715.486763] ? ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.494979] ? kfree+0xc1/0x520 |
| [ 715.498128] ? mutex_lock_io_nested+0x12a0/0x12a0 |
| [ 715.502837] ? kasan_set_free_info+0x20/0x30 |
| [ 715.507110] ? __kasan_slab_free+0x10b/0x140 |
| [ 715.511385] ? slab_free_freelist_hook+0xc7/0x220 |
| [ 715.516092] ? kfree+0xc1/0x520 |
| [ 715.519235] ? ice_deinit_lag+0x16c/0x220 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.527359] ? ice_remove+0x1cf/0x6a0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.535133] ? pci_device_remove+0xab/0x1d0 |
| [ 715.539318] ? __device_release_driver+0x35b/0x690 |
| [ 715.544110] ? driver_detach+0x214/0x2f0 |
| [ 715.548035] ? bus_remove_driver+0x11d/0x2f0 |
| [ 715.552309] ? pci_unregister_driver+0x26/0x250 |
| [ 715.556840] ? ice_module_exit+0xc/0x2f [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.564799] ? __do_sys_delete_module.constprop.0+0x2d8/0x4e0 |
| [ 715.570554] ? do_syscall_64+0x3b/0x90 |
| [ 715.574303] ? entry_SYSCALL_64_after_hwframe+0x44/0xae |
| [ 715.579529] ? start_flush_work+0x542/0x8f0 |
| [ 715.583719] ? ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.591923] ice_sq_send_cmd+0x78/0x14c0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.599960] ? wait_for_completion_io+0x250/0x250 |
| [ 715.604662] ? lock_acquire+0x196/0x200 |
| [ 715.608504] ? do_raw_spin_trylock+0xa5/0x160 |
| [ 715.612864] ice_sbq_rw_reg+0x1e6/0x2f0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.620813] ? ice_reset+0x130/0x130 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.628497] ? __debug_check_no_obj_freed+0x1e8/0x3c0 |
| [ 715.633550] ? trace_hardirqs_on+0x1c/0x130 |
| [ 715.637748] ice_write_phy_reg_e810+0x70/0xf0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.646220] ? do_raw_spin_trylock+0xa5/0x160 |
| [ 715.650581] ? ice_ptp_release+0x910/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.658797] ? ice_ptp_release+0x255/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.667013] ice_clear_phy_tstamp+0x2c/0x110 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.675403] ice_ptp_release+0x408/0x910 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.683440] ice_remove+0x560/0x6a0 [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.691037] ? _raw_spin_unlock_irqrestore+0x46/0x73 |
| [ 715.696005] pci_device_remove+0xab/0x1d0 |
| [ 715.700018] __device_release_driver+0x35b/0x690 |
| [ 715.704637] driver_detach+0x214/0x2f0 |
| [ 715.708389] bus_remove_driver+0x11d/0x2f0 |
| [ 715.712489] pci_unregister_driver+0x26/0x250 |
| [ 715.716857] ice_module_exit+0xc/0x2f [ice 9a7e1ec00971c89ecd3fe0d4dc7da2b3786a421d] |
| [ 715.724637] __do_sys_delete_module.constprop.0+0x2d8/0x4e0 |
| [ 715.730210] ? free_module+0x6d0/0x6d0 |
| [ 715.733963] ? task_work_run+0xe1/0x170 |
| [ 715.737803] ? exit_to_user_mode_loop+0x17f/0x1d0 |
| [ 715.742509] ? rcu_read_lock_sched_held+0x12/0x80 |
| [ 715.747215] ? trace_hardirqs_on+0x1c/0x130 |
| [ 715.751401] do_syscall_64+0x3b/0x90 |
| [ 715.754981] entry_SYSCALL_64_after_hwframe+0x44/0xae |
| [ 715.760033] RIP: 0033:0x7f4dfe59000b |
| [ 715.763612] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d 1e 0c 00 f7 d8 64 89 01 48 |
| [ 715.782357] RSP: 002b:00007ffe8c891708 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 |
| [ 715.789923] RAX: ffffffffffffffda RBX: 00005558a20468b0 RCX: 00007f4dfe59000b |
| [ 715.797054] RDX: 000000000000000a RSI: 0000000000000800 RDI: 00005558a2046918 |
| [ 715.804189] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 |
| [ 715.811319] R10: 00007f4dfe603ac0 R11: 0000000000000206 R12: 00007ffe8c891940 |
| [ 715.818455] R13: 00007ffe8c8920a3 R14: 00005558a20462a0 R15: 00005558a20468b0 |
| |
| Notice that this is the only case where we use the lock in this way. In |
| the cleanup kthread and work kthread the lock is only taken around the |
| bit accesses. This was done intentionally to avoid this kind of issue. |
| The way the lock is used, we only protect ordering of bit sets vs bit |
| clears. The Tx writers in the hot path don't need to be protected |
| against the entire kthread loop. The Tx queues threads only need to |
| ensure that they do not re-use an index that is currently in use. The |
| cleanup loop does not need to block all new set bits, since it will |
| re-queue itself if new timestamps are present. |
| |
| Fix the tracker flow so that it uses the same flow as the standard |
| cleanup thread. In addition, ensure the in_use bitmap actually gets |
| cleared properly. |
| |
| This fixes the warning and also avoids the potential deadlock that might |
| have occurred otherwise. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47449 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.14.4 with commit 46720ac66c21bf85e08823664b7b314b85e43f26 and fixed in 5.14.14 with commit 61616be899975404df44c20ab902464b60882cd7 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-47449 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/net/ethernet/intel/ice/ice_ptp.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/61616be899975404df44c20ab902464b60882cd7 |
| https://git.kernel.org/stable/c/4d4a223a86afe658cd878800f09458e8bb54415d |
