CVE-2021-47387
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: cpufreq: schedutil: Use kobject release() method to free sugov_tunables The struct sugov_tunables is protected by the kobject, so we can't free it directly. Otherwise we would get a call trace like this: ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30 WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100 Modules linked in: CPU: 3 PID: 720 Comm: a.sh Tainted: G W 5.14.0-rc1-next-20210715-yocto-standard+ #507 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--) pc : debug_print_object+0xb8/0x100 lr : debug_print_object+0xb8/0x100 sp : ffff80001ecaf910 x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80 x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000 x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20 x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010 x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365 x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69 x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0 x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001 x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000 x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000 Call trace: debug_print_object+0xb8/0x100 __debug_check_no_obj_freed+0x1c0/0x230 debug_check_no_obj_freed+0x20/0x88 slab_free_freelist_hook+0x154/0x1c8 kfree+0x114/0x5d0 sugov_exit+0xbc/0xc0 cpufreq_exit_governor+0x44/0x90 cpufreq_set_policy+0x268/0x4a8 store_scaling_governor+0xe0/0x128 store+0xc0/0xf0 sysfs_kf_write+0x54/0x80 kernfs_fop_write_iter+0x128/0x1c0 new_sync_write+0xf0/0x190 vfs_write+0x2d4/0x478 ksys_write+0x74/0x100 __arm64_sys_write+0x24/0x30 invoke_syscall.constprop.0+0x54/0xe0 do_el0_svc+0x64/0x158 el0_svc+0x2c/0xb0 el0t_64_sync_handler+0xb0/0xb8 el0t_64_sync+0x198/0x19c irq event stamp: 5518 hardirqs last enabled at (5517): [<ffff8000100cbd7c>] console_unlock+0x554/0x6c8 hardirqs last disabled at (5518): [<ffff800010fc0638>] el1_dbg+0x28/0xa0 softirqs last enabled at (5504): [<ffff8000100106e0>] __do_softirq+0x4d0/0x6c0 softirqs last disabled at (5483): [<ffff800010049548>] irq_exit+0x1b0/0x1b8 So split the original sugov_tunables_free() into two functions, sugov_clear_global_tunables() is just used to clear the global_tunables and the new sugov_tunables_free() is used as kobj_type::release to release the sugov_tunables safely.
CVSS Metrics
- v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Trends
Current EPSS score: 0.25%• Percentile: 17%
Techniques & Countermeasures
- CWE-763•Release of Invalid Pointer or Reference
The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.
Affected Systems
- debian•linux
< 5.10.84-1 | < 5.14.12-1 | < 5.14.12-1 | < 5.14.12-1
- ubuntu•linux
< 4.15.0-163.171 | < 5.4.0-91.102
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
< 4.15.0-1116.123 | < 5.4.0-1060.63
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.4
< 5.4.0-1060.63~18.04.1
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-fips
< 4.15.0-2057.59 | all | < 5.4.0-1069.73+fips2
- ubuntu•linux-aws-hwe
< 4.15.0-1116.123~16.04.1
- ubuntu•linux-azure
< 4.15.0-1127.140~14.04.1 | < 4.15.0-1127.140~16.04.1 | all | < 5.4.0-1064.67
- ubuntu•linux-azure-4.15
< 4.15.0-1127.140
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.4
< 5.4.0-1064.67~18.04.1
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fips
< 4.15.0-2039.43 | all | < 5.4.0-1073.76+fips1
- ubuntu•linux-bluefield
all | < 5.4.0-1022.25
- ubuntu•linux-fips
< 4.15.0-1073.82 | all | < 5.4.0-1037.43
- ubuntu•linux-gcp
< 4.15.0-1112.126~16.04.1 | all | < 5.4.0-1058.62
- ubuntu•linux-gcp-4.15
< 4.15.0-1112.126
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
- ubuntu•linux-gcp-5.19
all
- ubuntu•linux-gcp-5.3
all
- ubuntu•linux-gcp-5.4
< 5.4.0-1058.62~18.04.1
- ubuntu•linux-gcp-5.8
all
- ubuntu•linux-gcp-6.2
all
- ubuntu•linux-gcp-fips
< 4.15.0-2022.24 | all | < 5.4.0-1067.71~20.04.1
- ubuntu•linux-gke
all
- ubuntu•linux-gke-4.15
all
- ubuntu•linux-gke-5.15
all
- ubuntu•linux-gke-5.4
all
- ubuntu•linux-gkeop
< 5.4.0-1027.28
- ubuntu•linux-gkeop-5.4
all
- ubuntu•linux-hwe
< 4.15.0-163.171~16.04.1 | all
- ubuntu•linux-hwe-5.11
all
- ubuntu•linux-hwe-5.13
all
- ubuntu•linux-hwe-5.19
all
Showing first 50 affected entries in server-rendered view.
References (11)
- https://git.kernel.org/stable/c/cb4a53ba37532c861a5f3f22803391018a41849a
- https://git.kernel.org/stable/c/463c46705f321201090b69c4ad5da0cd2ce614c9
- https://git.kernel.org/stable/c/30d57cf2c4116ca6d34ecd1cac94ad84f8bc446c
- https://git.kernel.org/stable/c/67c98e023135ff81b8d52998a6fdb8ca0c518d82
- https://git.kernel.org/stable/c/a7d4fc84404d45d72f4490417e8cc3efa4af93f1
- https://git.kernel.org/stable/c/8d62aec52a8c5b1d25a2364b243fcc5098a2ede9
- https://git.kernel.org/stable/c/e5c6b312ce3cc97e90ea159446e6bfa06645364d
- https://ubuntu.com/security/CVE-2021-47387
- https://www.cve.org/CVERecord?id=CVE-2021-47387
- https://git.kernel.org/linus/e5c6b312ce3cc97e90ea159446e6bfa06645364d
- https://security-tracker.debian.org/tracker/CVE-2021-47387