CVE-2024-46795: Linux kernel · ksmbd: unset the binding mark of a reused connection
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1072.78~20.04.1 : update Linux kernel when convenient.
Data as of 29 Oct 2026, 22:34 UTC
- Patch
- Available – fixed in 5.15.0-1072.78~20.04.1, 5.15.0-1078.87~20.04.1, 5.15.0-1071.79~20.04.1 +52
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 18 Sep 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7100-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7123-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7144-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7154-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7155-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7156-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7154-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7194-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7196-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkeoppkg:deb/ubuntu/linux-gkeop?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: unset the binding mark of a reused connection Steve French reported null pointer dereference error from sha256 lib. cifs.ko can send session setup requests on reused connection. If reused connection is used for binding session, conn->binding can still remain true and generate_preauth_hash() will not set sess->Preauth_HashValue and it will be NULL. It is used as a material to create an encryption key in ksmbd_gen_smb311_encryptionkey. ->Preauth_HashValue cause null pointer dereference error from crypto_shash_update(). BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 8 PID: 429254 Comm: kworker/8:39 Hardware name: LENOVO 20MAS08500/20MAS08500, BIOS N2CET69W (1.52 ) Workqueue: ksmbd-io handle_ksmbd_work [ksmbd] RIP: 0010:lib_sha256_base_do_update.isra.0+0x11e/0x1d0 [sha256_ssse3] <TASK> ? show_regs+0x6d/0x80 ? __die+0x24/0x80 ? page_fault_oops+0x99/0x1b0 ? do_user_addr_fault+0x2ee/0x6b0 ? exc_page_fault+0x83/0x1b0 ? asm_exc_page_fault+0x27/0x30 ? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3] ? lib_sha256_base_do_update.isra.0+0x11e/0x1d0 [sha256_ssse3] ? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3] ? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3] _sha256_update+0x77/0xa0 [sha256_ssse3] sha256_avx2_update+0x15/0x30 [sha256_ssse3] crypto_shash_update+0x1e/0x40 hmac_update+0x12/0x20 crypto_shash_update+0x1e/0x40 generate_key+0x234/0x380 [ksmbd] generate_smb3encryptionkey+0x40/0x1c0 [ksmbd] ksmbd_gen_smb311_encryptionkey+0x72/0xa0 [ksmbd] ntlm_authenticate.isra.0+0x423/0x5d0 [ksmbd] smb2_sess_setup+0x952/0xaa0 [ksmbd] __process_request+0xa3/0x1d0 [ksmbd] __handle_ksmbd_work+0x1c4/0x2f0 [ksmbd] handle_ksmbd_work+0x2d/0xa0 [ksmbd] process_one_work+0x16c/0x350 worker_thread+0x306/0x440 ? __pfx_worker_thread+0x10/0x10 kthread+0xef/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x44/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK>
References
- ubuntu.com/security/CVE-2024-46795 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-46795 (opens in a new tab)
- git.kernel.org/linus/78c5a6f1f630172b19af4912e755e1da93ef0ab5 (opens in a new tab)
- git.kernel.org/stable/c/9914f1bd61d5e838bb1ab15a71076d37a6db65d1 (opens in a new tab)
- git.kernel.org/stable/c/93d54a4b59c4b3d803d20aa645ab5ca71f3b3b02 (opens in a new tab)
- git.kernel.org/stable/c/41bc256da7e47b679df87c7fc7a5b393052b9cce (opens in a new tab)
- git.kernel.org/stable/c/4c8496f44f5bb5c06cdef5eb130ab259643392a1 (opens in a new tab)
- git.kernel.org/stable/c/78c5a6f1f630172b19af4912e755e1da93ef0ab5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7123-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7144-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7154-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7155-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7156-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7154-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7194-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7196-1 (opens in a new tab)