CVE-2021-47219

scsi: scsi_debug: Fix out-of-bound read in resp_report_tgtpgs()

Severity Score

6.0

*CVSS v3

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: Fix out-of-bound read in resp_report_tgtpgs() The following issue was observed running syzkaller: BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:377 [inline]
BUG: KASAN: slab-out-of-bounds in sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831
Read of size 2132 at addr ffff8880aea95dc8 by task syz-executor.0/9815 CPU: 0 PID: 9815 Comm: syz-executor.0 Not tainted 4.19.202-00874-gfc0fe04215a9 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xe4/0x14a lib/dump_stack.c:118 print_address_description+0x73/0x280 mm/kasan/report.c:253 kasan_report_error mm/kasan/report.c:352 [inline] kasan_report+0x272/0x370 mm/kasan/report.c:410 memcpy+0x1f/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:377 [inline] sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831 fill_from_dev_buffer+0x14f/0x340 drivers/scsi/scsi_debug.c:1021 resp_report_tgtpgs+0x5aa/0x770 drivers/scsi/scsi_debug.c:1772 schedule_resp+0x464/0x12f0 drivers/scsi/scsi_debug.c:4429 scsi_debug_queuecommand+0x467/0x1390 drivers/scsi/scsi_debug.c:5835 scsi_dispatch_cmd+0x3fc/0x9b0 drivers/scsi/scsi_lib.c:1896 scsi_request_fn+0x1042/0x1810 drivers/scsi/scsi_lib.c:2034 __blk_run_queue_uncond block/blk-core.c:464 [inline] __blk_run_queue+0x1a4/0x380 block/blk-core.c:484 blk_execute_rq_nowait+0x1c2/0x2d0 block/blk-exec.c:78 sg_common_write.isra.19+0xd74/0x1dc0 drivers/scsi/sg.c:847 sg_write.part.23+0x6e0/0xd00 drivers/scsi/sg.c:716 sg_write+0x64/0xa0 drivers/scsi/sg.c:622 __vfs_write+0xed/0x690 fs/read_write.c:485
kill_bdev:block_device:00000000e138492c vfs_write+0x184/0x4c0 fs/read_write.c:549 ksys_write+0x107/0x240 fs/read_write.c:599 do_syscall_64+0xc2/0x560 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe We get 'alen' from command its type is int. If userspace passes a large
length we will get a negative 'alen'. Switch n, alen, and rlen to u32.

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Fix out-of-bound read in resp_report_tgtpgs() The following issue was observed running syzkaller: BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:377 [inline] BUG: KASAN: slab-out-of-bounds in sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831 Read of size 2132 at addr ffff8880aea95dc8 by task syz-executor.0/9815 CPU: 0 PID: 9815 Comm: syz-executor.0 Not tainted 4.19.202-00874-gfc0fe04215a9 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xe4/0x14a lib/dump_stack.c:118 print_address_description+0x73/0x280 mm/kasan/report.c:253 kasan_report_error mm/kasan/report.c:352 [inline] kasan_report+0x272/0x370 mm/kasan/report.c:410 memcpy+0x1f/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:377 [inline] sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831 fill_from_dev_buffer+0x14f/0x340 drivers/scsi/scsi_debug.c:1021 resp_report_tgtpgs+0x5aa/0x770 drivers/scsi/scsi_debug.c:1772 schedule_resp+0x464/0x12f0 drivers/scsi/scsi_debug.c:4429 scsi_debug_queuecommand+0x467/0x1390 drivers/scsi/scsi_debug.c:5835 scsi_dispatch_cmd+0x3fc/0x9b0 drivers/scsi/scsi_lib.c:1896 scsi_request_fn+0x1042/0x1810 drivers/scsi/scsi_lib.c:2034 __blk_run_queue_uncond block/blk-core.c:464 [inline] __blk_run_queue+0x1a4/0x380 block/blk-core.c:484 blk_execute_rq_nowait+0x1c2/0x2d0 block/blk-exec.c:78 sg_common_write.isra.19+0xd74/0x1dc0 drivers/scsi/sg.c:847 sg_write.part.23+0x6e0/0xd00 drivers/scsi/sg.c:716 sg_write+0x64/0xa0 drivers/scsi/sg.c:622 __vfs_write+0xed/0x690 fs/read_write.c:485 kill_bdev:block_device:00000000e138492c vfs_write+0x184/0x4c0 fs/read_write.c:549 ksys_write+0x107/0x240 fs/read_write.c:599 do_syscall_64+0xc2/0x560 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe We get 'alen' from command its type is int. If userspace passes a large length we will get a negative 'alen'. Switch n, alen, and rlen to u32.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Attack Vector

Local

Attack Complexity

Low

Authentication

Multiple

Confidentiality

Complete

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-04-10 CVE Reserved
2024-04-10 CVE Published
2024-12-19 CVE Updated
2025-03-18 EPSS 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/8440377e1a5644779b4c8d013aa2a917f5fc83c3	2021-11-26
https://git.kernel.org/stable/c/66523553fa62c7878fc5441dc4e82be71934eb77	2021-11-25
https://git.kernel.org/stable/c/f347c26836c270199de1599c3cd466bb7747caa9	2021-10-19

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"				< 5.10.82 Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.82"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.15.5 Search vendor "Linux" for product "Linux Kernel" and version " < 5.15.5"		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