cbcvebase.
CVE-2025-39925
published 2025-10-01

CVE-2025-39925: In the Linux kernel, the following vulnerability has been resolved: can: j1939: implement NETDEV_UNREGISTER notification handler syzbot is reporting…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.12%
2.1th percentile
In the Linux kernel, the following vulnerability has been resolved: can: j1939: implement NETDEV_UNREGISTER notification handler syzbot is reporting unregister_netdevice: waiting for vcan0 to become free. Usage count = 2 problem, for j1939 protocol did not have NETDEV_UNREGISTER notification handler for undoing changes made by j1939_sk_bind(). Commit 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback") expects that a call to j1939_priv_put() can be unconditionally delayed until j1939_sk_sock_destruct() is called. But we need to call j1939_priv_put() against an extra ref held by j1939_sk_bind() call (as a part of undoing changes made by j1939_sk_bind()) as soon as NETDEV_UNREGISTER notification fires (i.e. before j1939_sk_sock_destruct() is called via j1939_sk_release()). Otherwise, the extra ref on "struct j1939_priv" held by j1939_sk_bind() call prevents "struct net_device" from dropping the usage count to 1; making it impossible for unregister_netdevice() to continue. [mkl: remove space in front of label]

Affected

12 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.8-1 (forky)linux 6.16.8-1 (forky)
linuxlinux
linuxlinux>= 9d71dd0c70099914fcd063135da3c580865e924c < da9e8f429139928570407e8f90559b5d46c20262da9e8f429139928570407e8f90559b5d46c20262
linuxlinux>= 9d71dd0c70099914fcd063135da3c580865e924c < 7fcbe5b2c6a4b5407bf2241fdb71e0a390f6ab9a7fcbe5b2c6a4b5407bf2241fdb71e0a390f6ab9a
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.16.8-16.16.8-1
linuxlinux_kernel>= 5.4 < 6.16.86.16.8
msrcazl3_kernel_6.6.96.2-2_on_azure_linux_3.0
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_wireshark_3.4.14-1_on_cbl_mariner_2.0
msrccbl_mariner_2.0_arm
msrccbl_mariner_2.0_x64

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_msrc9.8CRITICAL
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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