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Message-ID: <6da55a6b-7852-4832-9541-3f3c45a09a3a@126.com>
Date:   Thu, 30 Nov 2023 11:10:08 +0800
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Subject: Re: [PATCH v2] net/mlx5e: Fix a race in command alloc flow
To:     Moshe Shemesh <moshe@nvidia.com>, saeedm@nvidia.com,
        leon@kernel.org, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, jackm@dev.mellanox.co.il,
        ogerlitz@mellanox.com, roland@purestorage.com, eli@mellanox.com
Cc:     dinghui@sangfor.com.cn, netdev@vger.kernel.org,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20231121115251.588436-1-lishifeng1992@126.com>
 <ce982860-4cc8-cfee-bf73-00f5183c23a3@nvidia.com>
From:   Shifeng Li <lishifeng1992@126.com>
In-Reply-To: <ce982860-4cc8-cfee-bf73-00f5183c23a3@nvidia.com>
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On 2023/11/27 0:13, Moshe Shemesh wrote:
> 
> 
> On 11/21/2023 1:52 PM, Shifeng Li wrote:
>> Fix a cmd->ent use after free due to a race on command entry.
>> Such race occurs when one of the commands releases its last refcount and
>> frees its index and entry while another process running command flush
>> flow takes refcount to this command entry. The process which handles
>> commands flush may see this command as needed to be flushed if the other
>> process allocated a ent->idx but didn't set ent to cmd->ent_arr in
>> cmd_work_handler(). Fix it by moving the assignment of cmd->ent_arr into
>> the spin lock.
>>
>> [70013.081955] BUG: KASAN: use-after-free in mlx5_cmd_trigger_completions+0x1e2/0x4c0 [mlx5_core]
>> [70013.081967] Write of size 4 at addr ffff88880b1510b4 by task kworker/26:1/1433361
>> [70013.081968]
>> [70013.081989] CPU: 26 PID: 1433361 Comm: kworker/26:1 Kdump: loaded Tainted: G           OE     4.19.90-25.17.v2101.osc.sfc.6.10.0.0030.ky10.x86_64+debug #1
>> [70013.082001] Hardware name: SANGFOR 65N32-US/ASERVER-G-2605, BIOS SSSS5203 08/19/2020
>> [70013.082028] Workqueue: events aer_isr
>> [70013.082053] Call Trace:
>> [70013.082067]  dump_stack+0x8b/0xbb
>> [70013.082086]  print_address_description+0x6a/0x270
>> [70013.082102]  kasan_report+0x179/0x2c0
>> [70013.082133]  ? mlx5_cmd_trigger_completions+0x1e2/0x4c0 [mlx5_core]
>> [70013.082173]  mlx5_cmd_trigger_completions+0x1e2/0x4c0 [mlx5_core]
>> [70013.082213]  ? mlx5_cmd_use_polling+0x20/0x20 [mlx5_core]
>> [70013.082223]  ? kmem_cache_free+0x1ad/0x1e0
>> [70013.082267]  mlx5_cmd_flush+0x80/0x180 [mlx5_core]
>> [70013.082304]  mlx5_enter_error_state+0x106/0x1d0 [mlx5_core]
>> [70013.082338]  mlx5_try_fast_unload+0x2ea/0x4d0 [mlx5_core]
>> [70013.082377]  remove_one+0x200/0x2b0 [mlx5_core]
>> [70013.082390]  ? __pm_runtime_resume+0x58/0x70
>> [70013.082409]  pci_device_remove+0xf3/0x280
>> [70013.082426]  ? pcibios_free_irq+0x10/0x10
>> [70013.082439]  device_release_driver_internal+0x1c3/0x470
>> [70013.082453]  pci_stop_bus_device+0x109/0x160
>> [70013.082468]  pci_stop_and_remove_bus_device+0xe/0x20
>> [70013.082485]  pcie_do_fatal_recovery+0x167/0x550
>> [70013.082493]  aer_isr+0x7d2/0x960
>> [70013.082510]  ? aer_get_device_error_info+0x420/0x420
>> [70013.082526]  ? __schedule+0x821/0x2040
>> [70013.082536]  ? strscpy+0x85/0x180
>> [70013.082543]  process_one_work+0x65f/0x12d0
>> [70013.082556]  worker_thread+0x87/0xb50
>> [70013.082563]  ? __kthread_parkme+0x82/0xf0
>> [70013.082569]  ? process_one_work+0x12d0/0x12d0
>> [70013.082571]  kthread+0x2e9/0x3a0
>> [70013.082579]  ? kthread_create_worker_on_cpu+0xc0/0xc0
>> [70013.082592]  ret_from_fork+0x1f/0x40
>>
>> Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
>> Signed-off-by: Shifeng Li<lishifeng1992@126.com>
> 
> Fixes tag should be :
> Fixes: 50b2412b7e78 ("net/mlx5: Avoid possible free of command entry while timeout comp handler")
> 
> Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
> 
I have sent v3.

Thanks!

> Thanks!