CVE-2021-47578

scsi: scsi_debug: Don't call kcalloc() if size arg is zero

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved:

scsi: scsi_debug: Don't call kcalloc() if size arg is zero

If the size arg to kcalloc() is zero, it returns ZERO_SIZE_PTR. Because of
that, for a following NULL pointer check to work on the returned pointer,
kcalloc() must not be called with the size arg equal to zero. Return early
without error before the kcalloc() call if size arg is zero.

BUG: KASAN: null-ptr-deref in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: null-ptr-deref in sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974
Write of size 4 at addr 0000000000000010 by task syz-executor.1/22789

CPU: 1 PID: 22789 Comm: syz-executor.1 Not tainted 5.15.0-syzk #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106
__kasan_report mm/kasan/report.c:446 [inline]
kasan_report.cold.14+0x112/0x117 mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x1a3/0x210 mm/kasan/generic.c:189
memcpy+0x3b/0x60 mm/kasan/shadow.c:66
memcpy include/linux/fortify-string.h:191 [inline]
sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974
do_dout_fetch drivers/scsi/scsi_debug.c:2954 [inline]
do_dout_fetch drivers/scsi/scsi_debug.c:2946 [inline]
resp_verify+0x49e/0x930 drivers/scsi/scsi_debug.c:4276
schedule_resp+0x4d8/0x1a70 drivers/scsi/scsi_debug.c:5478
scsi_debug_queuecommand+0x8c9/0x1ec0 drivers/scsi/scsi_debug.c:7533
scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1520 [inline]
scsi_queue_rq+0x16b0/0x2d40 drivers/scsi/scsi_lib.c:1699
blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1639
__blk_mq_sched_dispatch_requests+0x28f/0x590 block/blk-mq-sched.c:325
blk_mq_sched_dispatch_requests+0x105/0x190 block/blk-mq-sched.c:358
__blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1761
__blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1838
blk_mq_run_hw_queue+0x18d/0x350 block/blk-mq.c:1891
blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474
blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:62
blk_execute_rq+0xdb/0x360 block/blk-exec.c:102
sg_scsi_ioctl drivers/scsi/scsi_ioctl.c:621 [inline]
scsi_ioctl+0x8bb/0x15c0 drivers/scsi/scsi_ioctl.c:930
sg_ioctl_common+0x172d/0x2710 drivers/scsi/sg.c:1112
sg_ioctl+0xa2/0x180 drivers/scsi/sg.c:1165
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: scsi: scsi_debug: no llamar a kcalloc() si el tamaño arg es cero. Si el tamaño arg de kcalloc() es cero, devuelve ZERO_SIZE_PTR. Por eso, para que una siguiente verificación de puntero NULL funcione en el puntero devuelto, no se debe llamar a kcalloc() con el tamaño arg igual a cero. Regrese temprano sin errores antes de la llamada a kcalloc() si el tamaño arg es cero. ERROR: KASAN: null-ptr-deref en memcpy include/linux/fortify-string.h:191 [en línea] ERROR: KASAN: null-ptr-deref en sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 Escritura de tamaño 4 en la dirección 0000000000000010 por tarea syz-executor.1/22789 CPU: 1 PID: 22789 Comm: syz-executor.1 No contaminado 5.15.0-syzk #1 Nombre del hardware: Red Hat KVM, BIOS 1.13.0-2 Seguimiento de llamadas : __dump_stack lib/dump_stack.c:88 [en línea] dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:446 [en línea] kasan_report.cold.14+0x112/0x117 mm/kasan/ report.c:459 check_region_inline mm/kasan/generic.c:183 [en línea] kasan_check_range+0x1a3/0x210 mm/kasan/generic.c:189 memcpy+0x3b/0x60 mm/kasan/shadow.c:66 memcpy include/linux /fortify-string.h:191 [en línea] sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 controladores do_dout_fetch/scsi/scsi_debug.c:2954 [en línea] controladores do_dout_fetch/scsi/scsi_debug.c:2946 [en línea] resp_verify +0x49e/0x930 controladores/scsi/scsi_debug.c:4276 Schedule_resp+0x4d8/0x1a70 controladores/scsi/scsi_debug.c:5478 scsi_debug_queuecommand+0x8c9/0x1ec0 controladores/scsi/scsi_debug.c:7533 controladores scsi_dispatch_cmd/scsi /scsi_lib.c: 1520 [en línea] scsi_queue_rq+0x16b0/0x2d40 drivers/scsi/scsi_lib.c:1699 blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1639 __blk_mq_sched_dispatch_requests+0x28f/0x590 lk-mq-sched.c:325 blk_mq_sched_dispatch_requests+ 0x105/0x190 block/blk-mq-sched.c:358 __blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1761 __blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1838 cola+0x18d/0x350 bloque/negro -mq.c:1891 blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474 blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:62 blk_execute_rq+0xdb/0x360 block/blk-exec.c:102 sg_scsi_ioctl controladores/scsi/scsi_ioctl.c:621 [en línea] scsi_ioctl+0x8bb/0x15c0 controladores/scsi/scsi_ioctl.c:930 sg_ioctl_common+0x172d/0x2710 controladores/scsi/sg.c:1112 sg_ioctl+0xa2/0 controladores x180/scsi/ SG.C: 1165 VFS_IOCTL FS/IOCTL.C: 51 [INLINE] __DO_SYS_IOCTL FS/IOCTL.C: 874 [INLINE] __SE_SYS_IOCTL FS/IOCTL.C: 860 [Inline] __X64_SY 60 do_syscall_x64 arch/x86/entry/common.c:50 [en línea] do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80 Entry_SYSCALL_64_after_hwframe+0x44/0xae

*Credits: N/A

CVSS Scores

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-24 CVE Reserved
2024-06-19 CVE Published
2024-08-27 EPSS Updated
2024-11-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (3)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/aa1f912712a109b6306746133de7e5343f016b26	2021-12-22
https://git.kernel.org/stable/c/47d11d35203b0aa13533634e270fe2c3610e531b	2021-12-22
https://git.kernel.org/stable/c/3344b58b53a76199dae48faa396e9fc37bf86992	2021-11-05

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"				< 5.10.88 Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.88"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.15.11 Search vendor "Linux" for product "Linux Kernel" and version " < 5.15.11"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.16 Search vendor "Linux" for product "Linux Kernel" and version " < 5.16"		en		Affected