CVE-2022-49513

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> cpufreq: governor: Use kobject release() method to free dbs_data<br /> <br /> The struct dbs_data embeds a struct gov_attr_set and<br /> the struct gov_attr_set embeds a kobject. Since every kobject must have<br /> a release() method and we can&amp;#39;t use kfree() to free it directly,<br /> so introduce cpufreq_dbs_data_release() to release the dbs_data via<br /> the kobject::release() method. This fixes the calltrace like below:<br /> <br /> ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x34<br /> WARNING: CPU: 12 PID: 810 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100<br /> Modules linked in:<br /> CPU: 12 PID: 810 Comm: sh Not tainted 5.16.0-next-20220120-yocto-standard+ #536<br /> Hardware name: Marvell OcteonTX CN96XX board (DT)<br /> pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)<br /> pc : debug_print_object+0xb8/0x100<br /> lr : debug_print_object+0xb8/0x100<br /> sp : ffff80001dfcf9a0<br /> x29: ffff80001dfcf9a0 x28: 0000000000000001 x27: ffff0001464f0000<br /> x26: 0000000000000000 x25: ffff8000090e3f00 x24: ffff80000af60210<br /> x23: ffff8000094dfb78 x22: ffff8000090e3f00 x21: ffff0001080b7118<br /> x20: ffff80000aeb2430 x19: ffff800009e8f5e0 x18: 0000000000000000<br /> x17: 0000000000000002 x16: 00004d62e58be040 x15: 013590470523aff8<br /> x14: ffff8000090e1828 x13: 0000000001359047 x12: 00000000f5257d14<br /> x11: 0000000000040591 x10: 0000000066c1ffea x9 : ffff8000080d15e0<br /> x8 : ffff80000a1765a8 x7 : 0000000000000000 x6 : 0000000000000001<br /> x5 : ffff800009e8c000 x4 : ffff800009e8c760 x3 : 0000000000000000<br /> x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0001474ed040<br /> Call trace:<br /> debug_print_object+0xb8/0x100<br /> __debug_check_no_obj_freed+0x1d0/0x25c<br /> debug_check_no_obj_freed+0x24/0xa0<br /> kfree+0x11c/0x440<br /> cpufreq_dbs_governor_exit+0xa8/0xac<br /> cpufreq_exit_governor+0x44/0x90<br /> cpufreq_set_policy+0x29c/0x570<br /> store_scaling_governor+0x110/0x154<br /> store+0xb0/0xe0<br /> sysfs_kf_write+0x58/0x84<br /> kernfs_fop_write_iter+0x12c/0x1c0<br /> new_sync_write+0xf0/0x18c<br /> vfs_write+0x1cc/0x220<br /> ksys_write+0x74/0x100<br /> __arm64_sys_write+0x28/0x3c<br /> invoke_syscall.constprop.0+0x58/0xf0<br /> do_el0_svc+0x70/0x170<br /> el0_svc+0x54/0x190<br /> el0t_64_sync_handler+0xa4/0x130<br /> el0t_64_sync+0x1a0/0x1a4<br /> irq event stamp: 189006<br /> hardirqs last enabled at (189005): [] finish_task_switch.isra.0+0xe0/0x2c0<br /> hardirqs last disabled at (189006): [] el1_dbg+0x24/0xa0<br /> softirqs last enabled at (188966): [] __do_softirq+0x4b0/0x6a0<br /> softirqs last disabled at (188957): [] __irq_exit_rcu+0x108/0x1a4<br /> <br /> [ rjw: Because can be freed by the gov_attr_set_put() in<br /> cpufreq_dbs_governor_exit() now, it is also necessary to put the<br /> invocation of the governor -&gt;exit() callback into the new<br /> cpufreq_dbs_data_release() function. ]