CVE-2026-98119: Linux kernel · netfs: break unbuffered write when netfs_alloc_subrequest() fails
Source GCVE Database
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| 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
- nvd.nist.gov/vuln/detail/CVE-2026-98119 (opens in a new tab)
- git.kernel.org/stable/c/19f246c795e940dc5f11cd5bc0cb1e81bc7b7090 (opens in a new tab)
- git.kernel.org/stable/c/8fb45a934661419c04a44d4cfea1e0df7dcf2805 (opens in a new tab)
- git.kernel.org/stable/c/cf6f93b8b06acf57de62dacbe71a3b99c68656a7 (opens in a new tab)