From: Kevin Hao <haokexin@gmail.com> stable inclusion from stable-v5.15.91 commit a1964688582d26af1328e19b658933659fb54337 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBP6N1 CVE: CVE-2022-49513 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit a85ee6401a47ae3fc64ba506cacb3e7873823c65 upstream. The struct dbs_data embeds a struct gov_attr_set and the struct gov_attr_set embeds a kobject. Since every kobject must have a release() method and we can't use kfree() to free it directly, so introduce cpufreq_dbs_data_release() to release the dbs_data via the kobject::release() method. This fixes the calltrace like below: ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x34 WARNING: CPU: 12 PID: 810 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100 Modules linked in: CPU: 12 PID: 810 Comm: sh Not tainted 5.16.0-next-20220120-yocto-standard+ #536 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : debug_print_object+0xb8/0x100 lr : debug_print_object+0xb8/0x100 sp : ffff80001dfcf9a0 x29: ffff80001dfcf9a0 x28: 0000000000000001 x27: ffff0001464f0000 x26: 0000000000000000 x25: ffff8000090e3f00 x24: ffff80000af60210 x23: ffff8000094dfb78 x22: ffff8000090e3f00 x21: ffff0001080b7118 x20: ffff80000aeb2430 x19: ffff800009e8f5e0 x18: 0000000000000000 x17: 0000000000000002 x16: 00004d62e58be040 x15: 013590470523aff8 x14: ffff8000090e1828 x13: 0000000001359047 x12: 00000000f5257d14 x11: 0000000000040591 x10: 0000000066c1ffea x9 : ffff8000080d15e0 x8 : ffff80000a1765a8 x7 : 0000000000000000 x6 : 0000000000000001 x5 : ffff800009e8c000 x4 : ffff800009e8c760 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0001474ed040 Call trace: debug_print_object+0xb8/0x100 __debug_check_no_obj_freed+0x1d0/0x25c debug_check_no_obj_freed+0x24/0xa0 kfree+0x11c/0x440 cpufreq_dbs_governor_exit+0xa8/0xac cpufreq_exit_governor+0x44/0x90 cpufreq_set_policy+0x29c/0x570 store_scaling_governor+0x110/0x154 store+0xb0/0xe0 sysfs_kf_write+0x58/0x84 kernfs_fop_write_iter+0x12c/0x1c0 new_sync_write+0xf0/0x18c vfs_write+0x1cc/0x220 ksys_write+0x74/0x100 __arm64_sys_write+0x28/0x3c invoke_syscall.constprop.0+0x58/0xf0 do_el0_svc+0x70/0x170 el0_svc+0x54/0x190 el0t_64_sync_handler+0xa4/0x130 el0t_64_sync+0x1a0/0x1a4 irq event stamp: 189006 hardirqs last enabled at (189005): [<ffff8000080849d0>] finish_task_switch.isra.0+0xe0/0x2c0 hardirqs last disabled at (189006): [<ffff8000090667a4>] el1_dbg+0x24/0xa0 softirqs last enabled at (188966): [<ffff8000080106d0>] __do_softirq+0x4b0/0x6a0 softirqs last disabled at (188957): [<ffff80000804a618>] __irq_exit_rcu+0x108/0x1a4 [ rjw: Because can be freed by the gov_attr_set_put() in cpufreq_dbs_governor_exit() now, it is also necessary to put the invocation of the governor ->exit() callback into the new cpufreq_dbs_data_release() function. ] Fixes: c4435630361d ("cpufreq: governor: New sysfs show/store callbacks for governor tunables") Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zhang Kunbo <zhangkunbo@huawei.com> --- drivers/cpufreq/cpufreq_governor.c | 20 +++++++++++++------- drivers/cpufreq/cpufreq_governor.h | 1 + 2 files changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c index e5b01abd1da9..7a7884816b90 100644 --- a/drivers/cpufreq/cpufreq_governor.c +++ b/drivers/cpufreq/cpufreq_governor.c @@ -412,6 +412,15 @@ static void free_policy_dbs_info(struct policy_dbs_info *policy_dbs, gov->free(policy_dbs); } +static void cpufreq_dbs_data_release(struct kobject *kobj) +{ + struct dbs_data *dbs_data = to_dbs_data(to_gov_attr_set(kobj)); + struct dbs_governor *gov = dbs_data->gov; + + gov->exit(dbs_data); + kfree(dbs_data); +} + int cpufreq_dbs_governor_init(struct cpufreq_policy *policy) { struct dbs_governor *gov = dbs_governor_of(policy); @@ -449,6 +458,7 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy) goto free_policy_dbs_info; } + dbs_data->gov = gov; gov_attr_set_init(&dbs_data->attr_set, &policy_dbs->list); ret = gov->init(dbs_data); @@ -471,6 +481,7 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy) policy->governor_data = policy_dbs; gov->kobj_type.sysfs_ops = &governor_sysfs_ops; + gov->kobj_type.release = cpufreq_dbs_data_release; ret = kobject_init_and_add(&dbs_data->attr_set.kobj, &gov->kobj_type, get_governor_parent_kobj(policy), "%s", gov->gov.name); @@ -512,13 +523,8 @@ void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy) policy->governor_data = NULL; - if (!count) { - if (!have_governor_per_policy()) - gov->gdbs_data = NULL; - - gov->exit(dbs_data); - kfree(dbs_data); - } + if (!count && !have_governor_per_policy()) + gov->gdbs_data = NULL; free_policy_dbs_info(policy_dbs, gov); diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h index 8463f5def0f5..8be1c974b554 100644 --- a/drivers/cpufreq/cpufreq_governor.h +++ b/drivers/cpufreq/cpufreq_governor.h @@ -40,6 +40,7 @@ enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE}; /* Governor demand based switching data (per-policy or global). */ struct dbs_data { struct gov_attr_set attr_set; + struct dbs_governor *gov; void *tuners; unsigned int ignore_nice_load; unsigned int sampling_rate; -- 2.34.1