In the Linux kernel, the following vulnerability has been resolved:
can: j1939: fix errant WARN_ON_ONCE in j1939_session_deactivate
The conclusion "j1939_session_deactivate() should be called with a session ref-count of at least 2" is incorrect. In some concurrent scenarios, j1939_session_deactivate can be called with the session ref-count less than 2. But there is not any problem because it will check the session active state before session putting in j1939_session_deactivate_locked().
Here is the concurrent scenario of the problem reported by syzbot and my reproduction log.
cpu0 cpu1 j1939_xtp_rx_eoma j1939_xtp_rx_abort_one j1939_session_get_by_addr [kref == 2] j1939_session_get_by_addr [kref == 3] j1939_session_deactivate [kref == 2] j1939_session_put [kref == 1] j1939_session_completed j1939_session_deactivate WARN_ON_ONCE(kref < 2)
===================================================== WARNING: CPU: 1 PID: 21 at net/can/j1939/transport.c:1088 j1939_session_deactivate+0x5f/0x70 CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 5.14.0-rc7+ #32 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014 RIP: 0010:j1939_session_deactivate+0x5f/0x70 Call Trace: j1939_session_deactivate_activate_next+0x11/0x28 j1939_xtp_rx_eoma+0x12a/0x180 j1939_tp_recv+0x4a2/0x510 j1939_can_recv+0x226/0x380 can_rcv_filter+0xf8/0x220 can_receive+0x102/0x220 ? process_backlog+0xf0/0x2c0 can_rcv+0x53/0xf0 __netif_receive_skb_one_core+0x67/0x90 ? process_backlog+0x97/0x2c0 __netif_receive_skb+0x22/0x80
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Mar 31, 2025 | Mar 27, 2025 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Mar 27, 2025 |
| Ubuntu | — | Upgrade linux-lowlatencyUpgrade linux-aws-5.15Upgrade linuxUpgrade linux-hwe-5.15Upgrade linux-awsUpgrade linux-raspiUpgrade linux-azure-5.4Upgrade linux-azure-fipsUpgrade linux-aws-5.4Upgrade linux-gcp-fipsUpgrade linux-iotUpgrade linux-gcp-5.4Upgrade linux-nvidia-tegra-5.15Upgrade linux-ibm-5.4Upgrade linux-azureUpgrade linux-ibmUpgrade linux-kvmUpgrade linux-xilinx-zynqmpUpgrade linux-azure-5.15Upgrade linux-bluefieldUpgrade linux-riscv-5.15Upgrade linux-oracle-5.15Upgrade linux-gcpUpgrade linux-intel-iotgUpgrade linux-raspi-5.4Upgrade linux-oracleUpgrade linux-fipsUpgrade linux-oracle-5.4Upgrade linux-nvidiaUpgrade linux-realtimeUpgrade linux-gkeUpgrade linux-intel-iotg-5.15Upgrade linux-lowlatency-hwe-5.15Upgrade linux-gkeopUpgrade linux-hwe-5.4Upgrade linux-aws-fipsUpgrade linux-intel-iot-realtimeUpgrade linux-gcp-5.15 | Apr 1, 2025 | Mar 27, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | Mar 27, 2025 |
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