Hi Eugeniu, Thank you for the patch. Mauro, there's a question for you below. On Tue, Jun 02, 2020 at 09:50:16PM +0200, Eugeniu Rosca wrote: > In commit f3b98e3c4d2e16 ("media: vsp1: Provide support for extended > command pools"), the vsp pointer used for referencing the VSP1 device > structure from a command pool during vsp1_dl_ext_cmd_pool_destroy() was > not populated. > > Correctly assign the pointer to prevent the following > null-pointer-dereference when removing the device: > > [*] h3ulcb-kf #> > echo fea28000.vsp > /sys/bus/platform/devices/fea28000.vsp/driver/unbind > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028 > Mem abort info: > ESR = 0x96000006 > EC = 0x25: DABT (current EL), IL = 32 bits > SET = 0, FnV = 0 > EA = 0, S1PTW = 0 > Data abort info: > ISV = 0, ISS = 0x00000006 > CM = 0, WnR = 0 > user pgtable: 4k pages, 48-bit VAs, pgdp=00000007318be000 > [0000000000000028] pgd=00000007333a1003, pud=00000007333a6003, pmd=0000000000000000 > Internal error: Oops: 96000006 [#1] PREEMPT SMP > Modules linked in: > CPU: 1 PID: 486 Comm: sh Not tainted 5.7.0-rc6-arm64-renesas-00118-ge644645abf47 #185 > Hardware name: Renesas H3ULCB Kingfisher board based on r8a77951 (DT) > pstate: 40000005 (nZcv daif -PAN -UAO) > pc : vsp1_dlm_destroy+0xe4/0x11c > lr : vsp1_dlm_destroy+0xc8/0x11c > sp : ffff800012963b60 > x29: ffff800012963b60 x28: ffff0006f83fc440 > x27: 0000000000000000 x26: ffff0006f5e13e80 > x25: ffff0006f5e13ed0 x24: ffff0006f5e13ed0 > x23: ffff0006f5e13ed0 x22: dead000000000122 > x21: ffff0006f5e3a080 x20: ffff0006f5df2938 > x19: ffff0006f5df2980 x18: 0000000000000003 > x17: 0000000000000000 x16: 0000000000000016 > x15: 0000000000000003 x14: 00000000000393c0 > x13: ffff800011a5ec18 x12: ffff800011d8d000 > x11: ffff0006f83fcc68 x10: ffff800011a53d70 > x9 : ffff8000111f3000 x8 : 0000000000000000 > x7 : 0000000000210d00 x6 : 0000000000000000 > x5 : ffff800010872e60 x4 : 0000000000000004 > x3 : 0000000078068000 x2 : ffff800012781000 > x1 : 0000000000002c00 x0 : 0000000000000000 > Call trace: > vsp1_dlm_destroy+0xe4/0x11c > vsp1_wpf_destroy+0x10/0x20 > vsp1_entity_destroy+0x24/0x4c > vsp1_destroy_entities+0x54/0x130 > vsp1_remove+0x1c/0x40 > platform_drv_remove+0x28/0x50 > __device_release_driver+0x178/0x220 > device_driver_detach+0x44/0xc0 > unbind_store+0xe0/0x104 > drv_attr_store+0x20/0x30 > sysfs_kf_write+0x48/0x70 > kernfs_fop_write+0x148/0x230 > __vfs_write+0x18/0x40 > vfs_write+0xdc/0x1c4 > ksys_write+0x68/0xf0 > __arm64_sys_write+0x18/0x20 > el0_svc_common.constprop.0+0x70/0x170 > do_el0_svc+0x20/0x80 > el0_sync_handler+0x134/0x1b0 > el0_sync+0x140/0x180 > Code: b40000c2 f9403a60 d2800084 a9400663 (f9401400) > ---[ end trace 3875369841fb288a ]--- > > Fixes: f3b98e3c4d2e16 ("media: vsp1: Provide support for extended command pools") > Cc: stable@xxxxxxxxxxxxxxx # v4.19+ > Signed-off-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx> > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> > Tested-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Mauro, can this be applied as a v5.8 fix, or should I include it in a pull request for v5.9 ? > --- > > Changes in v2: > - Rephrased the description based on Kieran's proposal > - Added the Reviewed-by/Tested-by signatures > - No change in the contents > > --- > drivers/media/platform/vsp1/vsp1_dl.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/media/platform/vsp1/vsp1_dl.c b/drivers/media/platform/vsp1/vsp1_dl.c > index d7b43037e500..e07b135613eb 100644 > --- a/drivers/media/platform/vsp1/vsp1_dl.c > +++ b/drivers/media/platform/vsp1/vsp1_dl.c > @@ -431,6 +431,8 @@ vsp1_dl_cmd_pool_create(struct vsp1_device *vsp1, enum vsp1_extcmd_type type, > if (!pool) > return NULL; > > + pool->vsp1 = vsp1; > + > spin_lock_init(&pool->lock); > INIT_LIST_HEAD(&pool->free); > -- Regards, Laurent Pinchart