VULNERABILITY

Ubuntu: (Multiple Advisories) (CVE-2025-21806): Linux kernel vulnerabilities

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Ubuntu: (Multiple Advisories) (CVE-2025-21806): Linux kernel vulnerabilities

Severity
5
CVSS
(AV:L/AC:L/Au:S/C:N/I:N/A:C)
Published
02/27/2025
Created
05/21/2025
Added
05/20/2025
Modified
05/22/2025

Description

In the Linux kernel, the following vulnerability has been resolved: net: let net.core.dev_weight always be non-zero The following problem was encountered during stability test: (NULL net_device): NAPI poll function process_backlog+0x0/0x530 \ returned 1, exceeding its budget of 0. ------------[ cut here ]------------ list_add double add: new=ffff88905f746f48, prev=ffff88905f746f48, \ next=ffff88905f746e40. WARNING: CPU: 18 PID: 5462 at lib/list_debug.c:35 \ __list_add_valid_or_report+0xf3/0x130 CPU: 18 UID: 0 PID: 5462 Comm: ping Kdump: loaded Not tainted 6.13.0-rc7+ RIP: 0010:__list_add_valid_or_report+0xf3/0x130 Call Trace: ? __warn+0xcd/0x250 ? __list_add_valid_or_report+0xf3/0x130 enqueue_to_backlog+0x923/0x1070 netif_rx_internal+0x92/0x2b0 __netif_rx+0x15/0x170 loopback_xmit+0x2ef/0x450 dev_hard_start_xmit+0x103/0x490 __dev_queue_xmit+0xeac/0x1950 ip_finish_output2+0x6cc/0x1620 ip_output+0x161/0x270 ip_push_pending_frames+0x155/0x1a0 raw_sendmsg+0xe13/0x1550 __sys_sendto+0x3bf/0x4e0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x5b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e The reproduction command is as follows: sysctl -w net.core.dev_weight=0 ping 127.0.0.1 This is because when the napi's weight is set to 0, process_backlog() may return 0 and clear the NAPI_STATE_SCHED bit of napi->state, causing this napi to be re-polled in net_rx_action() until __do_softirq() times out. Since the NAPI_STATE_SCHED bit has been cleared, napi_schedule_rps() can be retriggered in enqueue_to_backlog(), causing this issue. Making the napi's weight always non-zero solves this problem. Triggering this issue requires system-wide admin (setting is not namespaced).

Solution(s)

  • ubuntu-upgrade-linux-image-5-15-0-1037-nvidia-tegra
  • ubuntu-upgrade-linux-image-5-15-0-1037-nvidia-tegra-rt
  • ubuntu-upgrade-linux-image-5-15-0-1066-gkeop
  • ubuntu-upgrade-linux-image-5-15-0-1076-ibm
  • ubuntu-upgrade-linux-image-5-15-0-1077-intel-iot-realtime
  • ubuntu-upgrade-linux-image-5-15-0-1078-nvidia
  • ubuntu-upgrade-linux-image-5-15-0-1078-nvidia-lowlatency
  • ubuntu-upgrade-linux-image-5-15-0-1079-intel-iotg
  • ubuntu-upgrade-linux-image-5-15-0-1080-kvm
  • ubuntu-upgrade-linux-image-5-15-0-1081-gke
  • ubuntu-upgrade-linux-image-5-15-0-1081-oracle
  • ubuntu-upgrade-linux-image-5-15-0-1083-gcp
  • ubuntu-upgrade-linux-image-5-15-0-1083-gcp-fips
  • ubuntu-upgrade-linux-image-5-15-0-1084-realtime
  • ubuntu-upgrade-linux-image-5-15-0-1089-azure
  • ubuntu-upgrade-linux-image-5-15-0-1089-azure-fips
  • ubuntu-upgrade-linux-image-5-15-0-140-fips
  • ubuntu-upgrade-linux-image-5-15-0-140-generic
  • ubuntu-upgrade-linux-image-5-15-0-140-generic-64k
  • ubuntu-upgrade-linux-image-5-15-0-140-generic-lpae
  • ubuntu-upgrade-linux-image-5-15-0-140-lowlatency
  • ubuntu-upgrade-linux-image-5-15-0-140-lowlatency-64k
  • ubuntu-upgrade-linux-image-5-4-0-1064-xilinx-zynqmp
  • ubuntu-upgrade-linux-image-5-4-0-1092-ibm
  • ubuntu-upgrade-linux-image-5-4-0-1133-kvm
  • ubuntu-upgrade-linux-image-5-4-0-1144-oracle
  • ubuntu-upgrade-linux-image-5-4-0-1149-gcp
  • ubuntu-upgrade-linux-image-5-4-0-1149-gcp-fips
  • ubuntu-upgrade-linux-image-5-4-0-1151-azure
  • ubuntu-upgrade-linux-image-5-4-0-1151-azure-fips
  • ubuntu-upgrade-linux-image-5-4-0-216-generic
  • ubuntu-upgrade-linux-image-5-4-0-216-generic-lpae
  • ubuntu-upgrade-linux-image-5-4-0-216-lowlatency
  • ubuntu-upgrade-linux-image-6-11-0-1010-realtime
  • ubuntu-upgrade-linux-image-6-11-0-1013-raspi
  • ubuntu-upgrade-linux-image-6-11-0-1015-azure
  • ubuntu-upgrade-linux-image-6-11-0-1015-azure-fde
  • ubuntu-upgrade-linux-image-6-11-0-1015-gcp
  • ubuntu-upgrade-linux-image-6-11-0-1015-gcp-64k
  • ubuntu-upgrade-linux-image-6-11-0-1022-oem
  • ubuntu-upgrade-linux-image-6-11-0-26-generic
  • ubuntu-upgrade-linux-image-6-11-0-26-generic-64k
  • ubuntu-upgrade-linux-image-azure
  • ubuntu-upgrade-linux-image-azure-cvm
  • ubuntu-upgrade-linux-image-azure-fde
  • ubuntu-upgrade-linux-image-azure-fips
  • ubuntu-upgrade-linux-image-azure-lts-20-04
  • ubuntu-upgrade-linux-image-azure-lts-22-04
  • ubuntu-upgrade-linux-image-fips
  • ubuntu-upgrade-linux-image-gcp
  • ubuntu-upgrade-linux-image-gcp-64k
  • ubuntu-upgrade-linux-image-gcp-fips
  • ubuntu-upgrade-linux-image-gcp-lts-20-04
  • ubuntu-upgrade-linux-image-gcp-lts-22-04
  • ubuntu-upgrade-linux-image-generic
  • ubuntu-upgrade-linux-image-generic-64k
  • ubuntu-upgrade-linux-image-generic-64k-hwe-24-04
  • ubuntu-upgrade-linux-image-generic-hwe-24-04
  • ubuntu-upgrade-linux-image-generic-lpae
  • ubuntu-upgrade-linux-image-gke
  • ubuntu-upgrade-linux-image-gke-5-15
  • ubuntu-upgrade-linux-image-gkeop
  • ubuntu-upgrade-linux-image-gkeop-5-15
  • ubuntu-upgrade-linux-image-ibm
  • ubuntu-upgrade-linux-image-intel-iot-realtime
  • ubuntu-upgrade-linux-image-intel-iotg
  • ubuntu-upgrade-linux-image-kvm
  • ubuntu-upgrade-linux-image-lowlatency
  • ubuntu-upgrade-linux-image-lowlatency-64k
  • ubuntu-upgrade-linux-image-lowlatency-64k-hwe-20-04
  • ubuntu-upgrade-linux-image-lowlatency-hwe-20-04
  • ubuntu-upgrade-linux-image-nvidia
  • ubuntu-upgrade-linux-image-nvidia-lowlatency
  • ubuntu-upgrade-linux-image-nvidia-tegra
  • ubuntu-upgrade-linux-image-nvidia-tegra-rt
  • ubuntu-upgrade-linux-image-oem
  • ubuntu-upgrade-linux-image-oem-24-04b
  • ubuntu-upgrade-linux-image-oem-osp1
  • ubuntu-upgrade-linux-image-oracle
  • ubuntu-upgrade-linux-image-oracle-lts-20-04
  • ubuntu-upgrade-linux-image-oracle-lts-22-04
  • ubuntu-upgrade-linux-image-raspi
  • ubuntu-upgrade-linux-image-realtime
  • ubuntu-upgrade-linux-image-virtual
  • ubuntu-upgrade-linux-image-virtual-hwe-24-04
  • ubuntu-upgrade-linux-image-xilinx-zynqmp

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