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

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-43158— xfs: fix freemap adjustments when adding xattrs to leaf blocks

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xfs驱动在向叶块添加扩展属性时freemap调整错误，导致断言失败。

CVSS 8.8 · High EPSS 0.47% · P39

Possible ATT&CK Techniques 1 AI

T1068 · Exploitation for Privilege Escalation

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< d08976725355b9d54d8332fce223fa281cc304a5 affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< 6a8737afbccc340e718e0b22577312826390be8b affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< a396b3d73d51355e50acdb403ba9c4cae4c1174e affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< 38613c01f69e1e77e6b8acab1e8ac665d01c2f15 affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< ef42a8766ff3fdf51cf72fb36d0859c09d134478 affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< 43f3b18679615a93bd848afde3602ba160637a46 affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< 24ce71852f2cee6581e2cbebc15489ed52bf63b7 affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2< 3eefc0c2b78444b64feeb3783c017d6adc3cd3ce affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-43158

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
xfs: fix freemap adjustments when adding xattrs to leaf blocks
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: xfs: fix freemap adjustments when adding xattrs to leaf blocks xfs/592 and xfs/794 both trip this assertion in the leaf block freemap adjustment code after ~20 minutes of running on my test VMs: ASSERT(ichdr->firstused >= ichdr->count * sizeof(xfs_attr_leaf_entry_t) + xfs_attr3_leaf_hdr_size(leaf)); Upon enabling quite a lot more debugging code, I narrowed this down to fsstress trying to set a local extended attribute with namelen=3 and valuelen=71. This results in an entry size of 80 bytes. At the start of xfs_attr3_leaf_add_work, the freemap looks like this: i 0 base 448 size 0 rhs 448 count 46 i 1 base 388 size 132 rhs 448 count 46 i 2 base 2120 size 4 rhs 448 count 46 firstused = 520 where "rhs" is the first byte past the end of the leaf entry array. This is inconsistent -- the entries array ends at byte 448, but freemap[1] says there's free space starting at byte 388! By the end of the function, the freemap is in worse shape: i 0 base 456 size 0 rhs 456 count 47 i 1 base 388 size 52 rhs 456 count 47 i 2 base 2120 size 4 rhs 456 count 47 firstused = 440 Important note: 388 is not aligned with the entries array element size of 8 bytes. Based on the incorrect freemap, the name area starts at byte 440, which is below the end of the entries array! That's why the assertion triggers and the filesystem shuts down. How did we end up here? First, recall from the previous patch that the freemap array in an xattr leaf block is not intended to be a comprehensive map of all free space in the leaf block. In other words, it's perfectly legal to have a leaf block with: * 376 bytes in use by the entries array * freemap[0] has [base = 376, size = 8] * freemap[1] has [base = 388, size = 1500] * the space between 376 and 388 is free, but the freemap stopped tracking that some time ago If we add one xattr, the entries array grows to 384 bytes, and freemap[0] becomes [base = 384, size = 0]. So far, so good. But if we add a second xattr, the entries array grows to 392 bytes, and freemap[0] gets pushed up to [base = 392, size = 0]. This is bad, because freemap[1] hasn't been updated, and now the entries array and the free space claim the same space. The fix here is to adjust all freemap entries so that none of them collide with the entries array. Note that this fix relies on commit 2a2b5932db6758 ("xfs: fix attr leaf header freemap.size underflow") and the previous patch that resets zero length freemap entries to have base = 0.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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xfs驱动在向叶块添加扩展属性时freemap调整错误，导致断言失败。
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 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ~ d08976725355b9d54d8332fce223fa281cc304a5 -
Linux Linux 2.6.12 -

II. Public POCs for CVE-2026-43158

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-43158

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-43158 (8)

Same Patch Batch · Linux · 2026-05-06 · 224 CVEs total

CVE-2026-43208 9.8 CRITICAL net: do not pass flow_id to set_rps_cpu()
CVE-2026-43198 9.8 CRITICAL tcp: fix potential race in tcp_v6_syn_recv_sock()
CVE-2026-43125 9.8 CRITICAL dlm: validate length in dlm_search_rsb_tree
CVE-2026-43186 9.8 CRITICAL ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()
CVE-2026-43185 9.8 CRITICAL ksmbd: fix signededness bug in smb_direct_prepare_negotiation()
CVE-2026-43114 9.4 CRITICAL netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry
CVE-2026-43197 9.1 CRITICAL netconsole: avoid OOB reads, msg is not nul-terminated
CVE-2026-43117 9.1 CRITICAL btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()
CVE-2026-43083 9.1 CRITICAL net: ioam6: fix OOB and missing lock
CVE-2026-43187 8.8 HIGH xfs: delete attr leaf freemap entries when empty
CVE-2026-43110 8.8 HIGH wifi: brcmfmac: validate bsscfg indices in IF events
CVE-2026-43239 8.8 HIGH smb: client: prevent races in ->query_interfaces()
CVE-2026-43232 8.8 HIGH net: wan: farsync: Fix use-after-free bugs caused by unfinished tasklets
CVE-2026-43172 8.8 HIGH wifi: iwlwifi: fix 22000 series SMEM parsing
CVE-2026-43283 8.8 HIGH net: ethernet: ec_bhf: Fix dma_free_coherent() dma handle
CVE-2026-43176 8.8 HIGH wifi: rtw89: pci: validate release report content before using for RTL8922DE
CVE-2026-43113 8.8 HIGH wifi: wl1251: validate packet IDs before indexing tx_frames
CVE-2026-43215 8.8 HIGH cifs: Fix locking usage for tcon fields
CVE-2026-43249 8.8 HIGH 9p/xen: protect xen_9pfs_front_free against concurrent calls
CVE-2026-43112 8.8 HIGH fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath

Showing top 20 of 224 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-43158

No comments yet

Leave a comment