On Tue, Nov 21, 2023 at 03:52:51AM -0800, 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 I'm curious how did you get this error? I would expect to see some sort of lock in upper level which prevents it. Thanks
