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CVE-2026-31458— mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]

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，该漏洞源于多个sysfs命令路径在未验证contexts->nr的情况下访问contexts_arr[0]，可能导致空指针取消引用。

AI Predicted 7.8 Difficulty: Easy EPSS 0.16% · P5

Possible ATT&CK Techniques 1 AI

T1068 · Exploitation for Privilege Escalation

Affected Version Matrix 12

VendorProduct Version RangeStatus
Linux Linux 0ac32b8affb5a384253dbb8339bd2d0e91add0b7< aba546061341b56e9ffb37e1eb661a3628b6ec12 affected
0ac32b8affb5a384253dbb8339bd2d0e91add0b7< 1e8da792672481d603fa7cd0d815577220a3ee27 affected
0ac32b8affb5a384253dbb8339bd2d0e91add0b7< 708033c231bd782858f4ddbb46ee874a5a5fbdab affected
0ac32b8affb5a384253dbb8339bd2d0e91add0b7< bbe03ad3fb9e714191757ca7b41582f930be7be2 affected
0ac32b8affb5a384253dbb8339bd2d0e91add0b7< 1bfe9fb5ed2667fb075682408b776b5273162615 affected
5.18 affected
< 5.18 unaffected
6.6.131≤ 6.6.* unaffected
… +4 more rows
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I. Basic Information for CVE-2026-31458

Vulnerability Information
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Vulnerability Title
mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0] Multiple sysfs command paths dereference contexts_arr[0] without first verifying that kdamond->contexts->nr == 1. A user can set nr_contexts to 0 via sysfs while DAMON is running, causing NULL pointer dereferences. In more detail, the issue can be triggered by privileged users like below. First, start DAMON and make contexts directory empty (kdamond->contexts->nr == 0). # damo start # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/nr_contexts Then, each of below commands will cause the NULL pointer dereference. # echo update_schemes_stats > state # echo update_schemes_tried_regions > state # echo update_schemes_tried_bytes > state # echo update_schemes_effective_quotas > state # echo update_tuned_intervals > state Guard all commands (except OFF) at the entry point of damon_sysfs_handle_cmd().
Source: CVE Program / CVE List V5
CVSS Information
N/A
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，该漏洞源于多个sysfs命令路径在未验证contexts->nr的情况下访问contexts_arr[0]，可能导致空指针取消引用。
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 0ac32b8affb5a384253dbb8339bd2d0e91add0b7 ~ aba546061341b56e9ffb37e1eb661a3628b6ec12 -
Linux Linux 5.18 -

II. Public POCs for CVE-2026-31458

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III. Intelligence Information for CVE-2026-31458

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Same Patch Batch · Linux · 2026-04-22 · 100 CVEs total

CVE-2026-31478 9.8 CRITICAL ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()
CVE-2026-31463 9.8 CRITICAL iomap: fix invalid folio access when i_blkbits differs from I/O granularity
CVE-2026-31444 9.8 CRITICAL ksmbd: fix use-after-free and NULL deref in smb_grant_oplock()
CVE-2026-31436 9.8 CRITICAL dmaengine: idxd: fix possible wrong descriptor completion in llist_abort_desc()
CVE-2026-31501 9.8 CRITICAL net: ti: icssg-prueth: fix use-after-free of CPPI descriptor in RX path
CVE-2026-31448 9.4 CRITICAL ext4: avoid infinite loops caused by residual data
CVE-2026-31450 8.8 HIGH ext4: publish jinode after initialization
CVE-2026-31432 8.8 HIGH ksmbd: fix OOB write in QUERY_INFO for compound requests
CVE-2026-31433 8.8 HIGH ksmbd: fix potencial OOB in get_file_all_info() for compound requests
CVE-2026-31435 8.8 HIGH netfs: Fix read abandonment during retry
CVE-2026-31476 8.2 HIGH ksmbd: do not expire session on binding failure
CVE-2026-31464 8.1 HIGH scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done()
CVE-2026-31513 8.1 HIGH Bluetooth: L2CAP: Fix stack-out-of-bounds read in l2cap_ecred_conn_req
CVE-2026-31488 7.8 HIGH drm/amd/display: Do not skip unrelated mode changes in DSC validation
CVE-2026-31494 7.8 HIGH net: macb: use the current queue number for stats
CVE-2026-31454 7.8 HIGH xfs: save ailp before dropping the AIL lock in push callbacks
CVE-2026-31502 7.8 HIGH team: fix header_ops type confusion with non-Ethernet ports
CVE-2026-31479 7.8 HIGH drm/xe: always keep track of remap prev/next
CVE-2026-31504 7.8 HIGH net: fix fanout UAF in packet_release() via NETDEV_UP race
CVE-2026-31505 7.8 HIGH iavf: fix out-of-bounds writes in iavf_get_ethtool_stats()

Showing top 20 of 100 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-31458

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