{
  "threat_severity" : "Moderate",
  "public_date" : "2024-08-17T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: xdp: fix invalid wait context of page_pool_destroy()",
    "id" : "2305492",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2305492"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-764",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nxdp: fix invalid wait context of page_pool_destroy()\nIf the driver uses a page pool, it creates a page pool with\npage_pool_create().\nThe reference count of page pool is 1 as default.\nA page pool will be destroyed only when a reference count reaches 0.\npage_pool_destroy() is used to destroy page pool, it decreases a\nreference count.\nWhen a page pool is destroyed, ->disconnect() is called, which is\nmem_allocator_disconnect().\nThis function internally acquires mutex_lock().\nIf the driver uses XDP, it registers a memory model with\nxdp_rxq_info_reg_mem_model().\nThe xdp_rxq_info_reg_mem_model() internally increases a page pool\nreference count if a memory model is a page pool.\nNow the reference count is 2.\nTo destroy a page pool, the driver should call both page_pool_destroy()\nand xdp_unreg_mem_model().\nThe xdp_unreg_mem_model() internally calls page_pool_destroy().\nOnly page_pool_destroy() decreases a reference count.\nIf a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we\nwill face an invalid wait context warning.\nBecause xdp_unreg_mem_model() calls page_pool_destroy() with\nrcu_read_lock().\nThe page_pool_destroy() internally acquires mutex_lock().\nSplat looks like:\n=============================\n[ BUG: Invalid wait context ]\n6.10.0-rc6+ #4 Tainted: G W\n-----------------------------\nethtool/1806 is trying to lock:\nffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150\nother info that might help us debug this:\ncontext-{5:5}\n3 locks held by ethtool/1806:\nstack backtrace:\nCPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ #4 f916f41f172891c800f2fed\nHardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021\nCall Trace:\n<TASK>\ndump_stack_lvl+0x7e/0xc0\n__lock_acquire+0x1681/0x4de0\n? _printk+0x64/0xe0\n? __pfx_mark_lock.part.0+0x10/0x10\n? __pfx___lock_acquire+0x10/0x10\nlock_acquire+0x1b3/0x580\n? mem_allocator_disconnect+0x73/0x150\n? __wake_up_klogd.part.0+0x16/0xc0\n? __pfx_lock_acquire+0x10/0x10\n? dump_stack_lvl+0x91/0xc0\n__mutex_lock+0x15c/0x1690\n? mem_allocator_disconnect+0x73/0x150\n? __pfx_prb_read_valid+0x10/0x10\n? mem_allocator_disconnect+0x73/0x150\n? __pfx_llist_add_batch+0x10/0x10\n? console_unlock+0x193/0x1b0\n? lockdep_hardirqs_on+0xbe/0x140\n? __pfx___mutex_lock+0x10/0x10\n? tick_nohz_tick_stopped+0x16/0x90\n? __irq_work_queue_local+0x1e5/0x330\n? irq_work_queue+0x39/0x50\n? __wake_up_klogd.part.0+0x79/0xc0\n? mem_allocator_disconnect+0x73/0x150\nmem_allocator_disconnect+0x73/0x150\n? __pfx_mem_allocator_disconnect+0x10/0x10\n? mark_held_locks+0xa5/0xf0\n? rcu_is_watching+0x11/0xb0\npage_pool_release+0x36e/0x6d0\npage_pool_destroy+0xd7/0x440\nxdp_unreg_mem_model+0x1a7/0x2a0\n? __pfx_xdp_unreg_mem_model+0x10/0x10\n? kfree+0x125/0x370\n? bnxt_free_ring.isra.0+0x2eb/0x500\n? bnxt_free_mem+0x5ac/0x2500\nxdp_rxq_info_unreg+0x4a/0xd0\nbnxt_free_mem+0x1356/0x2500\nbnxt_close_nic+0xf0/0x3b0\n? __pfx_bnxt_close_nic+0x10/0x10\n? ethnl_parse_bit+0x2c6/0x6d0\n? __pfx___nla_validate_parse+0x10/0x10\n? __pfx_ethnl_parse_bit+0x10/0x10\nbnxt_set_features+0x2a8/0x3e0\n__netdev_update_features+0x4dc/0x1370\n? ethnl_parse_bitset+0x4ff/0x750\n? __pfx_ethnl_parse_bitset+0x10/0x10\n? __pfx___netdev_update_features+0x10/0x10\n? mark_held_locks+0xa5/0xf0\n? _raw_spin_unlock_irqrestore+0x42/0x70\n? __pm_runtime_resume+0x7d/0x110\nethnl_set_features+0x32d/0xa20\nTo fix this problem, it uses rhashtable_lookup_fast() instead of\nrhashtable_lookup() with rcu_read_lock().\nUsing xa without rcu_read_lock() here is safe.\nxa is freed by __xdp_mem_allocator_rcu_free() and this is called by\ncall_rcu() of mem_xa_remove().\nThe mem_xa_remove() is called by page_pool_destroy() if a reference\ncount reaches 0.\nThe xa is already protected by the reference count mechanism well in the\ncontrol plane.\nSo removing rcu_read_lock() for page_pool_destroy() is safe." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-05-13T00:00:00Z",
    "advisory" : "RHSA-2025:6966",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.12.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-05-13T00:00:00Z",
    "advisory" : "RHSA-2025:6966",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.12.1.el9_6"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Will not fix",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Will not fix",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Will not fix",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2024-43834\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-43834\nhttps://lore.kernel.org/linux-cve-announce/2024081728-CVE-2024-43834-0140@gregkh/T" ],
  "name" : "CVE-2024-43834",
  "csaw" : false
}