In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix warning and UAF when destroy the MR list
If the MR allocate failed, the MR recovery work not initialized and list not cleared. Then will be warning and UAF when release the MR:
WARNING: CPU: 4 PID: 824 at kernel/workqueue.c:3066 __flush_work.isra.0+0xf7/0x110 CPU: 4 PID: 824 Comm: mount.cifs Not tainted 6.1.0-rc5+ #82 RIP: 0010:__flush_work.isra.0+0xf7/0x110 Call Trace: <TASK> __cancel_work_timer+0x2ba/0x2e0 smbd_destroy+0x4e1/0x990 _smbd_get_connection+0x1cbd/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
BUG: KASAN: use-after-free in smbd_destroy+0x4fc/0x990 Read of size 8 at addr ffff88810b156a08 by task mount.cifs/824 CPU: 4 PID: 824 Comm: mount.cifs Tainted: G W 6.1.0-rc5+ #82 Call Trace: dump_stack_lvl+0x34/0x44 print_report+0x171/0x472 kasan_report+0xad/0x130 smbd_destroy+0x4fc/0x990 _smbd_get_connection+0x1cbd/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Allocated by task 824: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x7a/0x90 _smbd_get_connection+0x1b6f/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Freed by task 824: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x143/0x1b0 __kmem_cache_free+0xc8/0x330 _smbd_get_connection+0x1c6a/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Let's initialize the MR recovery work before MR allocate to prevent the warning, remove the MRs from the list to prevent the UAF.
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-develUpgrade kernel-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade bpftoolUpgrade perf-debuginfoUpgrade kernelUpgrade perfUpgrade kernel-tools-debuginfoUpgrade kernel-livepatch-5.10.173-154.642Upgrade kernel-tools-develUpgrade bpftool-debuginfoUpgrade kernel-headersUpgrade kernel-toolsUpgrade kernel-debuginfo-common-x86_64Upgrade python-perf-debuginfoUpgrade python-perfUpgrade kernel-livepatch-5.15.102-61.139 | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade kernel-headersUpgrade kernel-debuginfoUpgrade python3-perf-debuginfoUpgrade kernel-libbpf-develUpgrade kernel-tools-debuginfoUpgrade kernel-tools-develUpgrade kernel-develUpgrade kernelUpgrade python3-perfUpgrade perf-debuginfoUpgrade perfUpgrade kernel-libbpfUpgrade bpftool-debuginfoUpgrade kernel-livepatch-6.1.19-30.43Upgrade bpftoolUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-libbpf-staticUpgrade kernel-toolsUpgrade kernel-debuginfo-common-aarch64 | Oct 16, 2025 | Sep 18, 2025 |
| Debian | — | Upgrade linux | Sep 22, 2025 | Sep 22, 2025 |
| Huawei Euleros 2_0_sp10 | — | Upgrade kernelUpgrade kernel-toolsUpgrade kernel-abi-stablelistsUpgrade kernel-tools-libsUpgrade python3-perf | Jan 15, 2026 | Jan 13, 2026 |
| Huawei Euleros 2_0_sp13 | — | Upgrade kernel-toolsUpgrade kernelUpgrade kernel-abi-stablelistsUpgrade bpftoolUpgrade kernel-tools-libsUpgrade python3-perf | Feb 3, 2026 | Jan 30, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Sep 18, 2025 |
| Ubuntu | — | Upgrade linux-nvidia-tegraUpgrade linux-azure-fipsUpgrade linux-kvmUpgrade linux-intel-iot-realtimeUpgrade linux-aws-fipsUpgrade linux-riscv-5.15Upgrade linux-lowlatencyUpgrade linux-hwe-5.15Upgrade linux-gcpUpgrade linux-gcp-5.4Upgrade linux-fipsUpgrade linux-lowlatency-hwe-5.15Upgrade linux-realtimeUpgrade linux-aws-5.15Upgrade linux-gcp-5.15Upgrade linux-bluefieldUpgrade linux-raspi-5.4Upgrade linux-gkeUpgrade linuxUpgrade linux-intel-iotg-5.15Upgrade linux-azure-5.15Upgrade linux-ibm-5.4Upgrade linux-nvidiaUpgrade linux-aws-5.4Upgrade linux-nvidia-tegra-5.15Upgrade linux-gcp-fipsUpgrade linux-ibmUpgrade linux-iotUpgrade linux-azure-5.4Upgrade linux-xilinx-zynqmpUpgrade linux-intel-iotgUpgrade linux-awsUpgrade linux-gkeopUpgrade linux-hwe-5.4Upgrade linux-oracle-5.15Upgrade linux-oracleUpgrade linux-oracle-5.4Upgrade linux-raspiUpgrade linux-azure | Sep 26, 2025 | Sep 18, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 15, 2025 | Sep 18, 2025 |
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