CVE-2024-46795

ksmbd: unset the binding mark of a reused connection

MEDIUM

5.5

CVSS Score

Published: September 18, 2024 at 07:12 AM UTC

Updated: June 17, 2026 at 07:55 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.3%

SSVC

No known exploit

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>

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

5.15 ≤ v < 5.15.1675.15 ≤ v < 6.1.1105.15 ≤ v < 6.10.105.15 ≤ v < 6.115.15 ≤ v < 6.6.515.16 ≤ v < 6.1.1106.2 ≤ v < 6.6.516.7 ≤ v < 6.10.106.11 rc1 6.11 rc2 6.11 rc3 6.11 rc4 6.11 rc5 6.11 rc6f5a544e3bab78142207e0242d22442db85ba1eff

Vendor states this is fixed in 41bc256da7e47b679df87c7fc7a5b393052b9cce (fixed)

Vendor states this is fixed in 4c8496f44f5bb5c06cdef5eb130ab259643392a1 (fixed)

Vendor states this is fixed in 78c5a6f1f630172b19af4912e755e1da93ef0ab5 (fixed)

Vendor states this is fixed in 93d54a4b59c4b3d803d20aa645ab5ca71f3b3b02 (fixed)

Vendor states this is fixed in 9914f1bd61d5e838bb1ab15a71076d37a6db65d1 (fixed)

Vendor states this is fixed in 5.15 (unaffected)

Vendor states this is fixed in 5.15.167 (unaffected)

Vendor states this is fixed in 6.1.110 (unaffected)

Vendor states this is fixed in 6.10.10 (unaffected)

Vendor states this is fixed in 6.11 (unaffected)

Vendor states this is fixed in 6.6.51 (unaffected)