cbcvebase.
CVE-2026-23255
published 2026-03-18

CVE-2026-23255: In the Linux kernel, the following vulnerability has been resolved: net: add proper RCU protection to /proc/net/ptype Yin Fengwei reported an RCU stall in…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.11%
1.7th percentile
In the Linux kernel, the following vulnerability has been resolved: net: add proper RCU protection to /proc/net/ptype Yin Fengwei reported an RCU stall in ptype_seq_show() and provided a patch. Real issue is that ptype_seq_next() and ptype_seq_show() violate RCU rules. ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev to get device name without any barrier. At the same time, concurrent writers can remove a packet_type structure (which is correctly freed after an RCU grace period) and clear pt->dev without an RCU grace period. Define ptype_iter_state to carry a dev pointer along seq_net_private: struct ptype_iter_state { struct seq_net_private p; struct net_device *dev; // added in this patch }; We need to record the device pointer in ptype_get_idx() and ptype_seq_next() so that ptype_seq_show() is safe against concurrent pt->dev changes. We also need to add full RCU protection in ptype_seq_next(). (Missing READ_ONCE() when reading list.next values) Many thanks to Dong Chenchen for providing a repro.

Affected

38 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.10-1 (forky)linux 6.18.10-1 (forky)
linuxlinux
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < e974a10a52618f7f57a4bce173a0ed96acd4e5dce974a10a52618f7f57a4bce173a0ed96acd4e5dc
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 002a73470b56848e4c81efeaaedd471e92d66d8d002a73470b56848e4c81efeaaedd471e92d66d8d
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < dcefd3f0b9ed8288654c75254bdcee8e1085e861dcefd3f0b9ed8288654c75254bdcee8e1085e861
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 589a530ae44d0c80f523fcfd1a15af8087f27d35589a530ae44d0c80f523fcfd1a15af8087f27d35
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f613e8b4afea0cd17c7168e8b00e25bc8d33175df613e8b4afea0cd17c7168e8b00e25bc8d33175d
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.18.10-16.18.10-1
linuxlinux_kernel>= 2.6.12 < 6.18.106.18.10
linuxlinux_kernel>= 2.6.12.1 < 6.6.1366.6.136
linuxlinux_kernel>= 6.13 < 6.18.106.18.10
linuxlinux_kernel>= 6.7 < 6.12.806.12.80
msrcazl3_kernel_6.6.126.1-1_on_azure_linux_3.0
ubuntulinux
ubuntulinux-aws
ubuntulinux-azure
ubuntulinux-azure-6.8
ubuntulinux-azure-fde
ubuntulinux-azure-fde-6.8
ubuntulinux-azure-fips
ubuntulinux-fips
ubuntulinux-gcp
ubuntulinux-gcp-6.8

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vendor_msrc4.7MEDIUM
vendor_redhat4.7MEDIUM
vendor_ubuntu2.0LOW
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