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CVE-2021-47191— scsi: scsi_debug: Fix out-of-bound read in resp_readcap16()

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel 存在安全漏洞，该漏洞源于resp_readcap16存在越界读取漏洞。

CVSS 7.1 · High EPSS 0.24% · P14

Affected Version Matrix 8

VendorProduct Version RangeStatus
Linux Linux c65b1445d153a66ca91b00c1f10187e495c17918< 3e20cb072679bdb47747ccc8bee3233a4cf0765a affected
c65b1445d153a66ca91b00c1f10187e495c17918< 5b8bed6464ad6653586e30df046185fd816ad999 affected
c65b1445d153a66ca91b00c1f10187e495c17918< 4e3ace0051e7e504b55d239daab8789dd89b863c affected
2.6.18 affected
< 2.6.18 unaffected
5.10.82≤ 5.10.* unaffected
5.15.5≤ 5.15.* unaffected
5.16≤ * unaffected
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I. Basic Information for CVE-2021-47191

Vulnerability Information
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Vulnerability Title
scsi: scsi_debug: Fix out-of-bound read in resp_readcap16()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Fix out-of-bound read in resp_readcap16() The following warning was observed running syzkaller: [ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in; [ 3813.830724] program syz-executor not setting count and/or reply_len properly [ 3813.836956] ================================================================== [ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0 [ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549 [ 3813.846612] Call Trace: [ 3813.846995] dump_stack+0x108/0x15f [ 3813.847524] print_address_description+0xa5/0x372 [ 3813.848243] kasan_report.cold+0x236/0x2a8 [ 3813.849439] check_memory_region+0x240/0x270 [ 3813.850094] memcpy+0x30/0x80 [ 3813.850553] sg_copy_buffer+0x157/0x1e0 [ 3813.853032] sg_copy_from_buffer+0x13/0x20 [ 3813.853660] fill_from_dev_buffer+0x135/0x370 [ 3813.854329] resp_readcap16+0x1ac/0x280 [ 3813.856917] schedule_resp+0x41f/0x1630 [ 3813.858203] scsi_debug_queuecommand+0xb32/0x17e0 [ 3813.862699] scsi_dispatch_cmd+0x330/0x950 [ 3813.863329] scsi_request_fn+0xd8e/0x1710 [ 3813.863946] __blk_run_queue+0x10b/0x230 [ 3813.864544] blk_execute_rq_nowait+0x1d8/0x400 [ 3813.865220] sg_common_write.isra.0+0xe61/0x2420 [ 3813.871637] sg_write+0x6c8/0xef0 [ 3813.878853] __vfs_write+0xe4/0x800 [ 3813.883487] vfs_write+0x17b/0x530 [ 3813.884008] ksys_write+0x103/0x270 [ 3813.886268] __x64_sys_write+0x77/0xc0 [ 3813.886841] do_syscall_64+0x106/0x360 [ 3813.887415] entry_SYSCALL_64_after_hwframe+0x44/0xa9 This issue can be reproduced with the following syzkaller log: r0 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x26e1, 0x0) r1 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='fd/3\x00') open_by_handle_at(r1, &(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000) r2 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x40782) write$binfmt_aout(r2, &(0x7f0000000340)=ANY=[@ANYBLOB="00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d"], 0x126) In resp_readcap16() we get "int alloc_len" value -1104926854, and then pass the huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This leads to OOB in sg_copy_buffer(). To solve this issue, define alloc_len as u32.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel 存在安全漏洞，该漏洞源于resp_readcap16存在越界读取漏洞。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux c65b1445d153a66ca91b00c1f10187e495c17918 ~ 3e20cb072679bdb47747ccc8bee3233a4cf0765a -
Linux Linux 2.6.18 -

II. Public POCs for CVE-2021-47191

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III. Intelligence Information for CVE-2021-47191

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Other References for CVE-2021-47191 (3)

Same Patch Batch · Linux · 2024-04-10 · 39 CVEs total

CVE-2021-47215 9.8 CRITICAL net/mlx5e: kTLS, Fix crash in RX resync flow
CVE-2021-47203 8.8 HIGH scsi: lpfc: Fix list_add() corruption in lpfc_drain_txq()
CVE-2021-47183 8.8 HIGH scsi: lpfc: Fix link down processing to address NULL pointer dereference
CVE-2021-47184 8.8 HIGH i40e: Fix NULL ptr dereference on VSI filter sync
CVE-2021-47188 7.8 HIGH scsi: ufs: core: Improve SCSI abort handling
CVE-2021-47197 7.8 HIGH net/mlx5e: nullify cq->dbg pointer in mlx5_debug_cq_remove()
CVE-2021-47196 7.8 HIGH RDMA/core: Set send and receive CQ before forwarding to the driver
CVE-2021-47209 7.8 HIGH sched/fair: Prevent dead task groups from regaining cfs_rq's
CVE-2021-47194 7.8 HIGH cfg80211: call cfg80211_stop_ap when switch from P2P_GO type
CVE-2024-26815 7.8 HIGH net/sched: taprio: proper TCA_TAPRIO_TC_ENTRY_INDEX check
CVE-2021-47200 7.8 HIGH drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap
CVE-2021-47189 7.8 HIGH btrfs: fix memory ordering between normal and ordered work functions
CVE-2021-47201 7.8 HIGH iavf: free q_vectors before queues in iavf_disable_vf
CVE-2021-47219 7.1 HIGH scsi: scsi_debug: Fix out-of-bound read in resp_report_tgtpgs()
CVE-2021-47205 clk: sunxi-ng: Unregister clocks/resets when unbinding
CVE-2021-47207 ALSA: gus: fix null pointer dereference on pointer block
CVE-2021-47206 usb: host: ohci-tmio: check return value after calling platform_get_resource()
CVE-2021-47199 net/mlx5e: CT, Fix multiple allocations and memleak of mod acts
CVE-2021-47210 usb: typec: tipd: Remove WARN_ON in tps6598x_block_read
CVE-2021-47211 ALSA: usb-audio: fix null pointer dereference on pointer cs_desc

Showing top 20 of 39 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2021-47191

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