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VulnerabilityPublished Updated

CVE-2026-98119: Linux kernel · netfs: break unbuffered write when netfs_alloc_subrequest() fails

Source GCVE Database

0
Authoritative record:CVE-2026-98119· Medium

Not known to be exploited · CVSS 5.5 Medium · fixed in cf6f93b8b06acf57de62dacbe71a3b99c68656a7 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 22:27 UTC

CVSS 3.1 base score
5.5Medium
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in cf6f93b8b06acf57de62dacbe71a3b99c68656a7, 19f246c795e940dc5f11cd5bc0cb1e81bc7b7090, 8fb45a934661419c04a44d4cfea1e0df7dcf2805
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade Linux kernel to cf6f93b8b06acf57de62dacbe71a3b99c68656a7, 19f246c795e940dc5f11cd5bc0cb1e81bc7b7090 or 8fb45a934661419c04a44d4cfea1e0df7dcf2805.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 288ace2f57c9d06dd2e42bd80d03747d879a4068, < cf6f93b8b06acf57de62dacbe71a3b99c68656a7
Fixed in
  • cf6f93b8b06acf57de62dacbe71a3b99c68656a7
LinuxLinuxAffected
  • ≥ 288ace2f57c9d06dd2e42bd80d03747d879a4068, < 19f246c795e940dc5f11cd5bc0cb1e81bc7b7090
Fixed in
  • 19f246c795e940dc5f11cd5bc0cb1e81bc7b7090
LinuxLinuxAffected
  • ≥ 288ace2f57c9d06dd2e42bd80d03747d879a4068, < 8fb45a934661419c04a44d4cfea1e0df7dcf2805
Fixed in
  • 8fb45a934661419c04a44d4cfea1e0df7dcf2805
LinuxLinuxAffected
  • =6.10
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: netfs: break unbuffered write when netfs_alloc_subrequest() fails syzbot reported a null-ptr-deref below [1] following a fault injection in netfs_alloc_subrequest(). [0] When netfs_alloc_subrequest() fails, subreq is NULL. Later, netfs_prepare_write() tries to initialize members of subreq(e.g., source), the issue in [1] is triggered. Let's handle the error of netfs_prepare_write() properly. [0] FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 Call Trace: netfs_alloc_subrequest+0x116/0x3f0 netfs_prepare_write+0x76/0x7b0 netfs_unbuffered_write+0x75c/0x2020 netfs_unbuffered_write_iter_locked+0x7d6/0xa80 netfs_unbuffered_write_iter+0x442/0x720 v9fs_file_write_iter+0xbf/0x100 vfs_write+0x6ac/0x1050 [1] KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af] RIP: 0010:netfs_prepare_write+0xbc/0x7b0 fs/netfs/write_issue.c:173 Call Trace: netfs_unbuffered_write+0x75c/0x2020 fs/netfs/direct_write.c:111 netfs_unbuffered_write_iter_locked+0x7d6/0xa80 fs/netfs/direct_write.c:290 netfs_unbuffered_write_iter+0x442/0x720 fs/netfs/direct_write.c:382 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:409 new_sync_write fs/read_write.c:595 [inline]

References

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