Re: [PATCH 1/2] can: m_can: m_can_plat_probe(): free can_net device in case probe fails

[Marc Kleine-Budde]

On 05.02.2021 15:25:58, Xulin Sun wrote:
> The can_net device is allocated through kvzalloc(), if the subsequent probe
> cases fail to initialize, it should free the can_net device that has been
> successfully allocated before.
> 
> To fix below memory leaks call trace:
> 
> unreferenced object 0xfffffc08418b0000 (size 32768):
> comm "kworker/0:1", pid 22, jiffies 4294893966 (age 931.976s)
> hex dump (first 32 bytes):
> 63 61 6e 25 64 00 00 00 00 00 00 00 00 00 00 00 can%d...........
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<000000003faec9cc>] __kmalloc+0x1a4/0x3e0
> [<00000000560b1cad>] kvmalloc_node+0xa0/0xb0
> [<0000000093bada32>] alloc_netdev_mqs+0x60/0x380
> [<0000000041ddbb53>] alloc_candev_mqs+0x6c/0x14c
> [<00000000d08c7529>] m_can_class_allocate_dev+0x64/0x18c
> [<000000009fef1617>] m_can_plat_probe+0x2c/0x1f4
> [<000000006fdcc497>] platform_drv_probe+0x5c/0xb0
> [<00000000fd0f0726>] really_probe+0xec/0x41c
> [<000000003ffa5158>] driver_probe_device+0x60/0xf0
> [<000000005986c77e>] __device_attach_driver+0xb0/0x100
> [<00000000757823bc>] bus_for_each_drv+0x8c/0xe0
> [<0000000059253919>] __device_attach+0xdc/0x180
> [<0000000035c2b9f1>] device_initial_probe+0x28/0x34
> [<0000000082e2c85c>] bus_probe_device+0xa4/0xb0
> [<00000000cc6181c3>] deferred_probe_work_func+0x7c/0xb0
> [<0000000001b85f22>] process_one_work+0x1ec/0x480
> 
> Signed-off-by: Xulin Sun <xulin.sun@xxxxxxxxxxxxx>

This patch doesn't apply to net/master, since v5.10 there is a
similar fix:

    85816aba460c can: m_can: Fix freeing of can device from peripherials

Please update to latest v5.10.x. If you're on a kernel that's still
supported, and you're using the latest stable of that kernel, and it
doesn't have that patch applied, ask on linux-stable to pick up that
patch.

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
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