CVE-2021-47387
cpufreq: schedutil: Use kobject release() method to free sugov_tunables
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
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.
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: cpufreq: schedutil: utilice el método kobject release() para liberar sugov_tunables. La estructura sugov_tunables está protegida por kobject, por lo que no podemos liberarla directamente. De lo contrario, obtendríamos un seguimiento de llamada como este: ODEBUG: activo libre (estado activo 0) tipo de objeto: timer_list sugerencia: delay_work_timer_fn+0x0/0x30 ADVERTENCIA: CPU: 3 PID: 720 en lib/debugobjects.c:505 debug_print_object+0xb8/ 0x100 Módulos vinculados en: CPU: 3 PID: 720 Comm: a.sh Contaminado: GW 5.14.0-rc1-next-20210715-yocto-standard+ #507 Nombre del hardware: Placa Marvell OcteonTX CN96XX (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: d80 x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000 x23: ffff80001142aa68 x22 : ffff800011043d80 x21: ffff00010de46f20 x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010 x17: 6e6968207473696c x16: 656d6974203a x15: 6570797420746365 x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69 x11: ffff8000124b1560 x10: 0012331520 x9: ffff8000100ca6b0 x8: 000000000017ffe8 x7: c0000000fffeffff x6: 0000000000000001 x5: ffff800011d8c000 x4: ffff800011d8c740 x3: 0000000000000000 x2: ffff0001108301c0 x1: ab3c90eedf9c0f00 x0: 0000000000000000 Rastreo de llamadas: xb8/0x100 __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 nuevo _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 sello de evento irq: 5518 hardirqs habilitado por última vez en ( 5517): [] consola_unlock+ 0x554/0x6c8 hardirqs deshabilitado por última vez en (5518): [] el1_dbg+0x28/0xa0 softirqs habilitado por última vez en (5504): [] __do_softirq+0x4d0/0x6c0 softirqs deshabilitado por última vez en (5483): ff800010049548 >] irq_exit+0x1b0/0x1b8 Entonces divida el sugov_tunables_free() original en dos funciones, sugov_clear_global_tunables() solo se usa para borrar los global_tunables y el nuevo sugov_tunables_free() se usa como kobj_type::release para liberar los sugov_tunables de forma segura.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-05-21 CVE Reserved
- 2024-05-21 CVE Published
- 2024-05-22 EPSS Updated
- 2024-08-04 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (8)
| URL | Tag | Source |
|---|---|---|
| https://git.kernel.org/stable/c/9bdcb44e391da5c41b98573bf0305a0e0b1c9569 | Vuln. Introduced |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.7 < 4.9.285 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 4.9.285" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.7 < 4.14.249 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 4.14.249" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.7 < 4.19.209 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 4.19.209" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.7 < 5.4.151 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 5.4.151" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.7 < 5.10.71 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 5.10.71" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.7 < 5.14.10 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 5.14.10" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.7 < 5.15 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 5.15" | en |
Affected
| ||||||