{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fix lockdep splat in qdisc_tree_reduce_backlog()\n\nqdisc_tree_reduce_backlog() is called with the qdisc lock held,\nnot RTNL.\n\nWe must use qdisc_lookup_rcu() instead of qdisc_lookup()\n\nsyzbot reported:\n\nWARNING: suspicious RCU usage\n6.1.74-syzkaller #0 Not tainted\n-----------------------------\nnet/sched/sch_api.c:305 suspicious rcu_dereference_protected() usage!\n\nother info that might help us debug this:\n\nrcu_scheduler_active = 2, debug_locks = 1\n3 locks held by udevd/1142:\n  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]\n  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]\n  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: net_tx_action+0x64a/0x970 net/core/dev.c:5282\n  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]\n  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: net_tx_action+0x754/0x970 net/core/dev.c:5297\n  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]\n  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]\n  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: qdisc_tree_reduce_backlog+0x84/0x580 net/sched/sch_api.c:792\n\nstack backtrace:\nCPU: 1 PID: 1142 Comm: udevd Not tainted 6.1.74-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nCall Trace:\n <TASK>\n  [<ffffffff85b85f14>] __dump_stack lib/dump_stack.c:88 [inline]\n  [<ffffffff85b85f14>] dump_stack_lvl+0x1b1/0x28f lib/dump_stack.c:106\n  [<ffffffff85b86007>] dump_stack+0x15/0x1e lib/dump_stack.c:113\n  [<ffffffff81802299>] lockdep_rcu_suspicious+0x1b9/0x260 kernel/locking/lockdep.c:6592\n  [<ffffffff84f0054c>] qdisc_lookup+0xac/0x6f0 net/sched/sch_api.c:305\n  [<ffffffff84f037c3>] qdisc_tree_reduce_backlog+0x243/0x580 net/sched/sch_api.c:811\n  [<ffffffff84f5b78c>] pfifo_tail_enqueue+0x32c/0x4b0 net/sched/sch_fifo.c:51\n  [<ffffffff84fbcf63>] qdisc_enqueue include/net/sch_generic.h:833 [inline]\n  [<ffffffff84fbcf63>] netem_dequeue+0xeb3/0x15d0 net/sched/sch_netem.c:723\n  [<ffffffff84eecab9>] dequeue_skb net/sched/sch_generic.c:292 [inline]\n  [<ffffffff84eecab9>] qdisc_restart net/sched/sch_generic.c:397 [inline]\n  [<ffffffff84eecab9>] __qdisc_run+0x249/0x1e60 net/sched/sch_generic.c:415\n  [<ffffffff84d7aa96>] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125\n  [<ffffffff84d85d29>] net_tx_action+0x7c9/0x970 net/core/dev.c:5313\n  [<ffffffff85e002bd>] __do_softirq+0x2bd/0x9bd kernel/softirq.c:616\n  [<ffffffff81568bca>] invoke_softirq kernel/softirq.c:447 [inline]\n  [<ffffffff81568bca>] __irq_exit_rcu+0xca/0x230 kernel/softirq.c:700\n  [<ffffffff81568ae9>] irq_exit_rcu+0x9/0x20 kernel/softirq.c:712\n  [<ffffffff85b89f52>] sysvec_apic_timer_interrupt+0x42/0x90 arch/x86/kernel/apic/apic.c:1107\n  [<ffffffff85c00ccb>] asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:656"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/sched/sch_api.c"
               ],
               "versions": [
                  {
                     "version": "9d9a38b5639f",
                     "lessThan": "b7d1ce2cc719",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d636fc5dd692",
                     "lessThan": "c040b99461a5",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d636fc5dd692",
                     "lessThan": "07696415526b",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d636fc5dd692",
                     "lessThan": "7eb322360b02",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/sched/sch_api.c"
               ],
               "versions": [
                  {
                     "version": "6.4",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "6.4",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.85",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.26",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.8.5",
                     "lessThanOrEqual": "6.8.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.9",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/b7d1ce2cc7192e8a037faa3f5d3ba72c25976460"
            },
            {
               "url": "https://git.kernel.org/stable/c/c040b99461a5bfc14c2d0cbb1780fcc3a4706c7e"
            },
            {
               "url": "https://git.kernel.org/stable/c/07696415526bee0607e495017369c7303a4792e1"
            },
            {
               "url": "https://git.kernel.org/stable/c/7eb322360b0266481e560d1807ee79e0cef5742b"
            }
         ],
         "title": "net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-35892",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}