Cloudanix VulnDB

CVE-2024-46796

High · 7.8

CVSS

7.8

EPSS

0.4%

Published

Sep 18, 2024

CISA due date

—

Cloudanix analysis

Monitor only SSVC: Track

A flaw in how Linux handles certain file operations over network shares can cause crashes or allow attackers to gain elevated access on affected machines.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Use After Free
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Double put of cfile reference in smb2_set_path_size when smb2_compound_op returns -EINVAL causes use-after-free of the fileinfo structure, leading to slab corruption during subsequent cifs_oplock_break workqueue processing.

Why it matters to the business

Linux systems mounting SMB shares may experience kernel panics or local privilege escalation during routine file operations, increasing downtime risk and potential compromise on servers with CIFS workloads.

How an attack unfolds

An attacker triggers file size changes or truncates on an SMB share mounted from Windows, causing the error path in compound operations that drops the cfile reference prematurely; later oplock break handling reuses the freed structure and triggers the use-after-free.

How to fix it

Upgrade the Linux kernel to 6.6.51 or apply the fix in commit 5a72d1edb0843e4c927a4096f81e631031c25c28; rebuild and reboot affected hosts.

How to confirm the fix worked

Confirm running kernel version is 6.6.51 or newer; re-execute fstests generic/013 against Windows Server targets and verify absence of KASAN reports in dmesg.

Typical attack path

  1. Mount remote SMB share via CIFS
  2. Invoke file truncation or setattr operations
  3. Force smb2_compound_op to return -EINVAL
  4. Trigger deferred file close and oplock break workqueue
  5. Access freed cfile structure during timer/work cancellation

How to detect it

Search kernel logs for KASAN slab-use-after-free reports involving detach_if_pending, cifs_oplock_break, or smb2_set_path_size; correlate with CIFS mount and workqueue activity.

  • BUG: KASAN: slab-use-after-free in detach_if_pending
  • cifs_oplock_break+0x4c1
  • smb2_set_path_size+0x228
  • _cifsFileInfo_put
  • Workqueue: cifsoplockd cifs_oplock_break [cifs]

What your security team should do

  • Prioritize kernel upgrades on all systems exposing CIFS mounts
  • Restrict untrusted SMB share access until patched
  • Enable kernel hardening features such as KASAN in test environments for early detection

The record

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double put of @cfile in smb2_set_path_size() If smb2_compound_op() is called with a valid @cfile and returned -EINVAL, we need to call cifs_get_writable_path() before retrying it as the reference of @cfile was already dropped by previous call. This fixes the following KASAN splat when running fstests generic/013 against Windows Server 2022: CIFS: Attempting to mount //w22-fs0/scratch run fstests generic/013 at 2024-09-02 19:48:59 ================================================================== BUG: KASAN: slab-use-after-free in detach_if_pending+0xab/0x200 Write of size 8 at addr ffff88811f1a3730 by task kworker/3:2/176 CPU: 3 UID: 0 PID: 176 Comm: kworker/3:2 Not tainted 6.11.0-rc6 #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 Workqueue: cifsoplockd cifs_oplock_break [cifs] Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 ? detach_if_pending+0xab/0x200 print_report+0x156/0x4d9 ? detach_if_pending+0xab/0x200 ? __virt_addr_valid+0x145/0x300 ? __phys_addr+0x46/0x90 ? detach_if_pending+0xab/0x200 kasan_report+0xda/0x110 ? detach_if_pending+0xab/0x200 detach_if_pending+0xab/0x200 timer_delete+0x96/0xe0 ? __pfx_timer_delete+0x10/0x10 ? rcu_is_watching+0x20/0x50 try_to_grab_pending+0x46/0x3b0 __cancel_work+0x89/0x1b0 ? __pfx___cancel_work+0x10/0x10 ? kasan_save_track+0x14/0x30 cifs_close_deferred_file+0x110/0x2c0 [cifs] ? __pfx_cifs_close_deferred_file+0x10/0x10 [cifs] ? __pfx_down_read+0x10/0x10 cifs_oplock_break+0x4c1/0xa50 [cifs] ? __pfx_cifs_oplock_break+0x10/0x10 [cifs] ? lock_is_held_type+0x85/0xf0 ? mark_held_locks+0x1a/0x90 process_one_work+0x4c6/0x9f0 ? find_held_lock+0x8a/0xa0 ? __pfx_process_one_work+0x10/0x10 ? lock_acquired+0x220/0x550 ? __list_add_valid_or_report+0x37/0x100 worker_thread+0x2e4/0x570 ? __kthread_parkme+0xd1/0xf0 ? __pfx_worker_thread+0x10/0x10 kthread+0x17f/0x1c0 ? kthread+0xda/0x1c0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 1118: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 cifs_new_fileinfo+0xc8/0x9d0 [cifs] cifs_atomic_open+0x467/0x770 [cifs] lookup_open.isra.0+0x665/0x8b0 path_openat+0x4c3/0x1380 do_filp_open+0x167/0x270 do_sys_openat2+0x129/0x160 __x64_sys_creat+0xad/0xe0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 83: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x70 poison_slab_object+0xe9/0x160 __kasan_slab_free+0x32/0x50 kfree+0xf2/0x300 process_one_work+0x4c6/0x9f0 worker_thread+0x2e4/0x570 kthread+0x17f/0x1c0 ret_from_fork+0x31/0x60 ret_from_fork_asm+0x1a/0x30 Last potentially related work creation: kasan_save_stack+0x30/0x50 __kasan_record_aux_stack+0xad/0xc0 insert_work+0x29/0xe0 __queue_work+0x5ea/0x760 queue_work_on+0x6d/0x90 _cifsFileInfo_put+0x3f6/0x770 [cifs] smb2_compound_op+0x911/0x3940 [cifs] smb2_set_path_size+0x228/0x270 [cifs] cifs_set_file_size+0x197/0x460 [cifs] cifs_setattr+0xd9c/0x14b0 [cifs] notify_change+0x4e3/0x740 do_truncate+0xfa/0x180 vfs_truncate+0x195/0x200 __x64_sys_truncate+0x109/0x150 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Affected packages

Ecosystem Package Introduced Fixed
Debian:13 linux 0 6.10.11-1
Linux Kernel 0 6.6.51
Mageia:9 kernel 0 6.6.52-1.mga9
Mageia:9 kernel-linus 0 6.6.52-1.mga9
Mageia:9 kmod-virtualbox 0 7.0.20-54.mga9
Mageia:9 kmod-xtables-addons 0 3.24-62.mga9
SUSE:Linux Enterprise High Availability Extension 15 SP6 kernel-default 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_10 0 1-150600.1.5.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_10 0 1-150600.13.5.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.47.2.150600.12.20.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco 0 6.4.0-15061.21.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco_debug 0 6.4.0-15061.21.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-source-coco 0 6.4.0-15061.21.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-syms-coco 0 6.4.0-15061.21.coco15sp6.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.47.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.47.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.47.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.47.2
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.34.2
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.34.2
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.34.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.47.2
SUSE:Real Time Module 15 SP6 kernel-rt 0 6.4.0-150600.10.34.1
SUSE:Real Time Module 15 SP6 kernel-rt_debug 0 6.4.0-150600.10.34.1
SUSE:Real Time Module 15 SP6 kernel-source-rt 0 6.4.0-150600.10.34.1
SUSE:Real Time Module 15 SP6 kernel-syms-rt 0 6.4.0-150600.10.34.1
Ubuntu:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure 0 No fix
Ubuntu:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:18.04:LTS linux-gcp 0 No fix
Ubuntu:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:18.04:LTS linux-hwe 0 No fix
Ubuntu:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-oem 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:20.04:LTS linux 0 5.4.0-9.12
Ubuntu:20.04:LTS linux-aws 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:20.04:LTS linux-aws-5.15 0 5.15.0-1014.18~20.04.1
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 5.4.0-1006.6
Ubuntu:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:20.04:LTS linux-azure-5.15 0 5.15.0-1007.8~20.04.1
Ubuntu:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:20.04:LTS linux-azure-fde-5.15 0 5.15.0-1019.24~20.04.1.1
Ubuntu:20.04:LTS linux-bluefield 0 5.4.0-1007.10
Ubuntu:20.04:LTS linux-gcp 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.15 0 5.15.0-1006.9~20.04.1
Ubuntu:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:20.04:LTS linux-gke 0 No fix
Ubuntu:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:20.04:LTS linux-gkeop 0 5.4.0-1008.9
Ubuntu:20.04:LTS linux-gkeop-5.15 0 5.15.0-1003.5~20.04.2
Ubuntu:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.15 0 5.15.0-33.34~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 5.4.0-1003.4
Ubuntu:20.04:LTS linux-ibm-5.15 0 5.15.0-1033.36~20.04.1
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 5.15.0-1003.5~20.04.1
Ubuntu:20.04:LTS linux-iot 0 5.4.0-1001.3
Ubuntu:20.04:LTS linux-kvm 0 5.4.0-1004.4
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 5.15.0-33.34~20.04.1
Ubuntu:20.04:LTS linux-oem-5.10 0 No fix
Ubuntu:20.04:LTS linux-oem-5.13 0 No fix
Ubuntu:20.04:LTS linux-oem-5.14 0 No fix
Ubuntu:20.04:LTS linux-oem-5.6 0 No fix
Ubuntu:20.04:LTS linux-oracle 0 5.4.0-1005.5
Ubuntu:20.04:LTS linux-oracle-5.11 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.13 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.15 0 5.15.0-1007.9~20.04.1
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 5.4.0-1007.7
Ubuntu:20.04:LTS linux-raspi2 0 No fix
Ubuntu:20.04:LTS linux-riscv 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.11 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.15 0 5.15.0-1015.17~20.04.1
Ubuntu:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 5.4.0-1020.24
Ubuntu:22.04:LTS linux 0 5.13.0-19.19
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 5.13.0-1005.6
Ubuntu:22.04:LTS linux-aws-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws-6.2 0 No fix
Ubuntu:22.04:LTS linux-aws-6.5 0 No fix
Ubuntu:22.04:LTS linux-azure 0 5.13.0-1006.7
Ubuntu:22.04:LTS linux-azure-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-6.2 0 No fix
Ubuntu:22.04:LTS linux-azure-6.5 0 No fix
Ubuntu:22.04:LTS linux-azure-fde 0 5.15.0-1019.24.1
Ubuntu:22.04:LTS linux-azure-fde-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp 0 5.13.0-1005.6
Ubuntu:22.04:LTS linux-gcp-5.19 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.5 0 No fix
Ubuntu:22.04:LTS linux-gke 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-gkeop 0 5.15.0-1001.2
Ubuntu:22.04:LTS linux-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 6.8.0-38.38~22.04.1
Ubuntu:22.04:LTS linux-ibm 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 No fix
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 5.15.0-1021.26
Ubuntu:22.04:LTS linux-intel-iotg 0 5.15.0-1004.6
Ubuntu:22.04:LTS linux-kvm 0 5.13.0-1004.4
Ubuntu:22.04:LTS linux-lowlatency 0 5.15.0-22.22
Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 6.8.0-38.38.1~22.04.2
Ubuntu:22.04:LTS linux-nvidia 0 5.15.0-1005.5
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 6.5.0-1004.4
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-oem-5.17 0 No fix
Ubuntu:22.04:LTS linux-oem-6.0 0 No fix
Ubuntu:22.04:LTS linux-oem-6.1 0 No fix
Ubuntu:22.04:LTS linux-oem-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle 0 5.13.0-1008.10
Ubuntu:22.04:LTS linux-oracle-6.5 0 No fix
Ubuntu:22.04:LTS linux-raspi 0 5.13.0-1008.9
Ubuntu:22.04:LTS linux-realtime 0 No fix
Ubuntu:22.04:LTS linux-riscv 0 No fix
Ubuntu:22.04:LTS linux-riscv-5.19 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.5 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.8 0 6.8.0-38.38.1~22.04.1
Ubuntu:22.04:LTS linux-starfive-5.19 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.2 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.5 0 No fix
Ubuntu:22.04:LTS linux-xilinx-zynqmp 0 5.15.0-1022.26
Ubuntu:22.04:LTS:for:NVIDIA:BlueField linux-bluefield 0 5.15.0-1011.13
Ubuntu:24.04:LTS linux 0 6.5.0-9.9
Ubuntu:24.04:LTS linux-aws 0 6.5.0-1008.8
Ubuntu:24.04:LTS linux-azure 0 6.5.0-1007.7
Ubuntu:24.04:LTS linux-gcp 0 6.5.0-1007.7
Ubuntu:24.04:LTS linux-gke 0 6.8.0-1003.5
Ubuntu:24.04:LTS linux-gkeop 0 6.8.0-1001.3
Ubuntu:24.04:LTS linux-ibm 0 6.5.0-1009.9
Ubuntu:24.04:LTS linux-lowlatency 0 6.5.0-9.9.1
Ubuntu:24.04:LTS linux-nvidia 0 6.8.0-1007.7
Ubuntu:24.04:LTS linux-nvidia-lowlatency 0 6.8.0-1009.9.1
Ubuntu:24.04:LTS linux-oem-6.8 0 6.8.0-1003.3
Ubuntu:24.04:LTS linux-oracle 0 6.5.0-1010.10
Ubuntu:24.04:LTS linux-raspi 0 6.5.0-1005.7
Ubuntu:24.04:LTS linux-raspi-realtime 0 No fix
Ubuntu:24.04:LTS linux-raspi-realtime 0 6.7.0-2001.1
Ubuntu:24.04:LTS linux-realtime 0 6.8.0-1008.19
Ubuntu:24.04:LTS linux-riscv 0 6.5.0-9.9.1
Ubuntu:Pro:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-hwe 0 No fix
Ubuntu:Pro:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-oem 0 No fix
Ubuntu:Pro:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:Pro:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:Pro:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:Pro:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-gke 0 No fix
Ubuntu:Pro:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:Pro:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-hwe-5.8 0 No fix

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