Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-74571— btrfs: skip global block reserve accounting for rescue mounts

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基金会开源的一个操作系统内核。 Linux kernel 6.5版本存在安全漏洞，该漏洞源于使用rescue=ibadroots挂载时，btrfs_read_roots允许继续挂载，导致根指针为NULL，btrfs_update_global_block_rsv基于功能位解引用缺失根，可能导致空指针解引用和内核崩溃。

AI Predicted 7.4 Difficulty: Moderate EPSS 0.14% · P4

Possible ATT&CK Techniques 1 AI

T1499 · Endpoint Denial of Service

Affected Version Matrix 10

VendorProduct Version RangeStatus
Linux Linux 8dbfc14fc736eb701089aff09645c3d4ad3decb1< 076349e4c8d11f6b58c4549976a513b2b4dc6df2 affected
8dbfc14fc736eb701089aff09645c3d4ad3decb1< 51a0e8399858621442807a26057bcd1cd3ced046 affected
cbec34d3021d47007a0334c634f7053dbaf93d02 affected
1e8087589b5cf6fa17adaf57b64cf1656d77dfec affected
6.1.43< 6.2 affected
6.4.8< 6.5 affected
6.5 affected
< 6.5 unaffected
… +2 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-74571

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
btrfs: skip global block reserve accounting for rescue mounts
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: skip global block reserve accounting for rescue mounts [BUG] Mounting with rescue=ibadroots after corrupting the block group tree root triggers a NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000100 RIP: 0010:btrfs_update_global_block_rsv+0x9d/0x1c0 [btrfs] Call Trace: fill_dummy_bgs+0xd4/0x120 [btrfs] open_ctree+0xc6e/0x1ca0 [btrfs] btrfs_get_tree+0x50d/0xa40 [btrfs] The same crash occurs with a corrupted raid stripe tree root, via btrfs_read_block_groups() instead of fill_dummy_bgs(). [CAUSE] With rescue=ibadroots, btrfs_read_roots() allows the mount to continue when either root cannot be read, leaving the corresponding root pointer NULL while its on-disk feature bit remains set. btrfs_update_global_block_rsv() then dereferences the missing root based on the feature bit alone. [FIX] Rescue mounts are fully read-only and cannot start transactions, so the global reserve is never consumed. Under btrfs_is_full_ro(), mark the reserve as full and return before performing the accounting. And since we need to check if the fs is mount fully RO, export fs_is_full_ro() as btrfs_is_full_ro(), and move it to fs.h. [ Squash the fs_is_full_ro() export commit into this one. ]
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基金会开源的一个操作系统内核。 Linux kernel 6.5版本存在安全漏洞，该漏洞源于使用rescue=ibadroots挂载时，btrfs_read_roots允许继续挂载，导致根指针为NULL，btrfs_update_global_block_rsv基于功能位解引用缺失根，可能导致空指针解引用和内核崩溃。
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 8dbfc14fc736eb701089aff09645c3d4ad3decb1 ~ 076349e4c8d11f6b58c4549976a513b2b4dc6df2 -
Linux Linux 6.5 -

II. Public POCs for CVE-2026-74571

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-74571

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-74571 (2)

Same Patch Batch · Linux · 2026-08-15 · 845 CVEs total

CVE-2026-74475 10.0 CRITICAL vxlan: use neigh_ha_snapshot() in route_shortcircuit()
CVE-2026-72421 10.0 CRITICAL ipv4: fib: Don't ignore error route in local/main tables.
CVE-2026-74280 10.0 CRITICAL crypto: marvell/octeontx - fix DMA cleanup using wrong loop index
CVE-2026-74309 10.0 CRITICAL vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler
CVE-2026-74279 10.0 CRITICAL crypto: cavium/cpt - fix DMA cleanup using wrong loop index
CVE-2026-72407 10.0 CRITICAL geneve: validate inner network offset in geneve_gro_complete()
CVE-2026-72408 10.0 CRITICAL geneve: gate GRO hint in geneve_gro_complete() on gs->gro_hint
CVE-2026-72493 9.9 CRITICAL net: serialize netif_running() check in enqueue_to_backlog()
CVE-2026-74495 9.8 CRITICAL igbvf: Fix leak in TX DMA error cleanup
CVE-2026-72339 9.8 CRITICAL qede: fix off-by-one in BD ring consumption on build_skb failure
CVE-2026-72065 9.8 CRITICAL net: mana: Validate the packet length reported by the NIC
CVE-2026-72064 9.8 CRITICAL net: mana: Sync page pool RX frags for CPU
CVE-2026-72137 9.8 CRITICAL xfrm: nat_keepalive: avoid double free on send error
CVE-2026-72249 9.8 CRITICAL netfilter: flowtable: use dst in this direction when pushing IPIP header
CVE-2026-72139 9.8 CRITICAL tcp: defer md5sig_info kfree past RCU grace period in tcp_connect
CVE-2026-74376 9.8 CRITICAL md/raid10: reset read_slot when reusing r10bio for discard
CVE-2026-72248 9.8 CRITICAL netfilter: flowtable: support IPIP tunnel with direct xmit
CVE-2026-72494 9.8 CRITICAL RDMA/irdma: Replace waitqueue and flag with completion
CVE-2026-72226 9.8 CRITICAL batman-adv: tt: prevent TVLV OOB check overflow
CVE-2026-72221 9.8 CRITICAL sunrpc: wait for in-flight TLS handshake callback when cancel loses race

Showing top 20 of 845 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-74571

No comments yet

Leave a comment