FKIE_CVE-2025-40251

Vulnerability from fkie_nvd - Published: 2025-12-04 16:16 - Updated: 2025-12-04 17:15
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: devlink: rate: Unset parent pointer in devl_rate_nodes_destroy The function devl_rate_nodes_destroy is documented to "Unset parent for all rate objects". However, it was only calling the driver-specific `rate_leaf_parent_set` or `rate_node_parent_set` ops and decrementing the parent's refcount, without actually setting the `devlink_rate->parent` pointer to NULL. This leaves a dangling pointer in the `devlink_rate` struct, which cause refcount error in netdevsim[1] and mlx5[2]. In addition, this is inconsistent with the behavior of `devlink_nl_rate_parent_node_set`, where the parent pointer is correctly cleared. This patch fixes the issue by explicitly setting `devlink_rate->parent` to NULL after notifying the driver, thus fulfilling the function's documented behavior for all rate objects. [1] repro steps: echo 1 > /sys/bus/netdevsim/new_device devlink dev eswitch set netdevsim/netdevsim1 mode switchdev echo 1 > /sys/bus/netdevsim/devices/netdevsim1/sriov_numvfs devlink port function rate add netdevsim/netdevsim1/test_node devlink port function rate set netdevsim/netdevsim1/128 parent test_node echo 1 > /sys/bus/netdevsim/del_device dmesg: refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 8 PID: 1530 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0 CPU: 8 UID: 0 PID: 1530 Comm: bash Not tainted 6.18.0-rc4+ #1 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:refcount_warn_saturate+0x42/0xe0 Call Trace: <TASK> devl_rate_leaf_destroy+0x8d/0x90 __nsim_dev_port_del+0x6c/0x70 [netdevsim] nsim_dev_reload_destroy+0x11c/0x140 [netdevsim] nsim_drv_remove+0x2b/0xb0 [netdevsim] device_release_driver_internal+0x194/0x1f0 bus_remove_device+0xc6/0x130 device_del+0x159/0x3c0 device_unregister+0x1a/0x60 del_device_store+0x111/0x170 [netdevsim] kernfs_fop_write_iter+0x12e/0x1e0 vfs_write+0x215/0x3d0 ksys_write+0x5f/0xd0 do_syscall_64+0x55/0x10f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [2] devlink dev eswitch set pci/0000:08:00.0 mode switchdev devlink port add pci/0000:08:00.0 flavour pcisf pfnum 0 sfnum 1000 devlink port function rate add pci/0000:08:00.0/group1 devlink port function rate set pci/0000:08:00.0/32768 parent group1 modprobe -r mlx5_ib mlx5_fwctl mlx5_core dmesg: refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 7 PID: 16151 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0 CPU: 7 UID: 0 PID: 16151 Comm: bash Not tainted 6.17.0-rc7_for_upstream_min_debug_2025_10_02_12_44 #1 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:refcount_warn_saturate+0x42/0xe0 Call Trace: <TASK> devl_rate_leaf_destroy+0x8d/0x90 mlx5_esw_offloads_devlink_port_unregister+0x33/0x60 [mlx5_core] mlx5_esw_offloads_unload_rep+0x3f/0x50 [mlx5_core] mlx5_eswitch_unload_sf_vport+0x40/0x90 [mlx5_core] mlx5_sf_esw_event+0xc4/0x120 [mlx5_core] notifier_call_chain+0x33/0xa0 blocking_notifier_call_chain+0x3b/0x50 mlx5_eswitch_disable_locked+0x50/0x110 [mlx5_core] mlx5_eswitch_disable+0x63/0x90 [mlx5_core] mlx5_unload+0x1d/0x170 [mlx5_core] mlx5_uninit_one+0xa2/0x130 [mlx5_core] remove_one+0x78/0xd0 [mlx5_core] pci_device_remove+0x39/0xa0 device_release_driver_internal+0x194/0x1f0 unbind_store+0x99/0xa0 kernfs_fop_write_iter+0x12e/0x1e0 vfs_write+0x215/0x3d0 ksys_write+0x5f/0xd0 do_syscall_64+0x53/0x1f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/542f45486f1ce2d2dde75bd85aca0389ef7046c3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/715d9cda646a8a38ea8b2bb5afb679a7464055e2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c70df6c17d389cc743f0eb30160e2d6bc6910db8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f94c1a114ac209977bdf5ca841b98424295ab1f0
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndevlink: rate: Unset parent pointer in devl_rate_nodes_destroy\n\nThe function devl_rate_nodes_destroy is documented to \"Unset parent for\nall rate objects\". However, it was only calling the driver-specific\n`rate_leaf_parent_set` or `rate_node_parent_set` ops and decrementing\nthe parent\u0027s refcount, without actually setting the\n`devlink_rate-\u003eparent` pointer to NULL.\n\nThis leaves a dangling pointer in the `devlink_rate` struct, which cause\nrefcount error in netdevsim[1] and mlx5[2]. In addition, this is\ninconsistent with the behavior of `devlink_nl_rate_parent_node_set`,\nwhere the parent pointer is correctly cleared.\n\nThis patch fixes the issue by explicitly setting `devlink_rate-\u003eparent`\nto NULL after notifying the driver, thus fulfilling the function\u0027s\ndocumented behavior for all rate objects.\n\n[1]\nrepro steps:\necho 1 \u003e /sys/bus/netdevsim/new_device\ndevlink dev eswitch set netdevsim/netdevsim1 mode switchdev\necho 1 \u003e /sys/bus/netdevsim/devices/netdevsim1/sriov_numvfs\ndevlink port function rate add netdevsim/netdevsim1/test_node\ndevlink port function rate set netdevsim/netdevsim1/128 parent test_node\necho 1 \u003e /sys/bus/netdevsim/del_device\n\ndmesg:\nrefcount_t: decrement hit 0; leaking memory.\nWARNING: CPU: 8 PID: 1530 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0\nCPU: 8 UID: 0 PID: 1530 Comm: bash Not tainted 6.18.0-rc4+ #1 NONE\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014\nRIP: 0010:refcount_warn_saturate+0x42/0xe0\nCall Trace:\n \u003cTASK\u003e\n devl_rate_leaf_destroy+0x8d/0x90\n __nsim_dev_port_del+0x6c/0x70 [netdevsim]\n nsim_dev_reload_destroy+0x11c/0x140 [netdevsim]\n nsim_drv_remove+0x2b/0xb0 [netdevsim]\n device_release_driver_internal+0x194/0x1f0\n bus_remove_device+0xc6/0x130\n device_del+0x159/0x3c0\n device_unregister+0x1a/0x60\n del_device_store+0x111/0x170 [netdevsim]\n kernfs_fop_write_iter+0x12e/0x1e0\n vfs_write+0x215/0x3d0\n ksys_write+0x5f/0xd0\n do_syscall_64+0x55/0x10f0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n[2]\ndevlink dev eswitch set pci/0000:08:00.0 mode switchdev\ndevlink port add pci/0000:08:00.0 flavour pcisf pfnum 0 sfnum 1000\ndevlink port function rate add pci/0000:08:00.0/group1\ndevlink port function rate set pci/0000:08:00.0/32768 parent group1\nmodprobe -r mlx5_ib mlx5_fwctl mlx5_core\n\ndmesg:\nrefcount_t: decrement hit 0; leaking memory.\nWARNING: CPU: 7 PID: 16151 at lib/refcount.c:31 refcount_warn_saturate+0x42/0xe0\nCPU: 7 UID: 0 PID: 16151 Comm: bash Not tainted 6.17.0-rc7_for_upstream_min_debug_2025_10_02_12_44 #1 NONE\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\nRIP: 0010:refcount_warn_saturate+0x42/0xe0\nCall Trace:\n \u003cTASK\u003e\n devl_rate_leaf_destroy+0x8d/0x90\n mlx5_esw_offloads_devlink_port_unregister+0x33/0x60 [mlx5_core]\n mlx5_esw_offloads_unload_rep+0x3f/0x50 [mlx5_core]\n mlx5_eswitch_unload_sf_vport+0x40/0x90 [mlx5_core]\n mlx5_sf_esw_event+0xc4/0x120 [mlx5_core]\n notifier_call_chain+0x33/0xa0\n blocking_notifier_call_chain+0x3b/0x50\n mlx5_eswitch_disable_locked+0x50/0x110 [mlx5_core]\n mlx5_eswitch_disable+0x63/0x90 [mlx5_core]\n mlx5_unload+0x1d/0x170 [mlx5_core]\n mlx5_uninit_one+0xa2/0x130 [mlx5_core]\n remove_one+0x78/0xd0 [mlx5_core]\n pci_device_remove+0x39/0xa0\n device_release_driver_internal+0x194/0x1f0\n unbind_store+0x99/0xa0\n kernfs_fop_write_iter+0x12e/0x1e0\n vfs_write+0x215/0x3d0\n ksys_write+0x5f/0xd0\n do_syscall_64+0x53/0x1f0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53"
    }
  ],
  "id": "CVE-2025-40251",
  "lastModified": "2025-12-04T17:15:08.283",
  "metrics": {},
  "published": "2025-12-04T16:16:18.663",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/542f45486f1ce2d2dde75bd85aca0389ef7046c3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/715d9cda646a8a38ea8b2bb5afb679a7464055e2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c70df6c17d389cc743f0eb30160e2d6bc6910db8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f94c1a114ac209977bdf5ca841b98424295ab1f0"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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