| Message ID | 20230419-ffa_fixes_6-4-v2-1-d9108e43a176@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | firmware: arm_ffa: Some fixes for v6.4 | expand |
diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c index f29d77ecf72d..36bd5423c2f0 100644 --- a/drivers/firmware/arm_ffa/bus.c +++ b/drivers/firmware/arm_ffa/bus.c @@ -53,7 +53,8 @@ static void ffa_device_remove(struct device *dev) { struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver); - ffa_drv->remove(to_ffa_dev(dev)); + if (ffa_drv->remove) + ffa_drv->remove(to_ffa_dev(dev)); } static int ffa_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
Currently ffa_drv->remove() is called unconditionally from ffa_device_remove(). Since the driver registration doesn't check for it and allows it to be registered without .remove callback, we need to check for the presence of it before executing it from ffa_device_remove() to above a NULL pointer dereference like the one below: | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | Mem abort info: | ESR = 0x0000000086000004 | EC = 0x21: IABT (current EL), IL = 32 bits | SET = 0, FnV = 0 | EA = 0, S1PTW = 0 | FSC = 0x04: level 0 translation fault | user pgtable: 4k pages, 48-bit VAs, pgdp=0000000881cc8000 | [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 | Internal error: Oops: 0000000086000004 [#1] PREEMPT SMP | CPU: 3 PID: 130 Comm: rmmod Not tainted 6.3.0-rc7 #6 | Hardware name: FVP Base RevC (DT) | pstate: 63402809 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=-c) | pc : 0x0 | lr : ffa_device_remove+0x20/0x2c | Call trace: | 0x0 | device_release_driver_internal+0x16c/0x260 | driver_detach+0x90/0xd0 | bus_remove_driver+0xdc/0x11c | driver_unregister+0x30/0x54 | ffa_driver_unregister+0x14/0x20 | cleanup_module+0x18/0xeec | __arm64_sys_delete_module+0x234/0x378 | invoke_syscall+0x40/0x108 | el0_svc_common+0xb4/0xf0 | do_el0_svc+0x30/0xa4 | el0_svc+0x2c/0x7c | el0t_64_sync_handler+0x84/0xf0 | el0t_64_sync+0x190/0x194 Fixes: 244f5d597e1e ("firmware: arm_ffa: Add missing remove callback to ffa_bus_type") Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- drivers/firmware/arm_ffa/bus.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)