{"cve":"CVE-2024-36979","nvd":{"published":"2024-06-19T14:15:13.620","modified":"2026-08-04T11:18:38.480","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: mst: fix vlan use-after-free\n\nsyzbot reported a suspicious rcu usage[1] in bridge's mst code. While\nfixing it I noticed that nothing prevents a vlan to be freed while\nwalking the list from the same path (br forward delay timer). Fix the rcu\nusage and also make sure we are not accessing freed memory by making\nbr_mst_vlan_set_state use rcu read lock.\n\n[1]\n WARNING: suspicious RCU usage\n 6.9.0-rc6-syzkaller #0 Not tainted\n -----------------------------\n net/bridge/br_private.h:1599 suspicious rcu_dereference_protected() usage!\n ...\n stack backtrace:\n CPU: 1 PID: 8017 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024\n Call Trace:\n  <IRQ>\n  __dump_stack lib/dump_stack.c:88 [inline]\n  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114\n  lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712\n  nbp_vlan_group net/bridge/br_private.h:1599 [inline]\n  br_mst_set_state+0x1ea/0x650 net/bridge/br_mst.c:105\n  br_set_state+0x28a/0x7b0 net/bridge/br_stp.c:47\n  br_forward_delay_timer_expired+0x176/0x440 net/bridge/br_stp_timer.c:88\n  call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793\n  expire_timers kernel/time/timer.c:1844 [inline]\n  __run_timers kernel/time/timer.c:2418 [inline]\n  __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2429\n  run_timer_base kernel/time/timer.c:2438 [inline]\n  run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448\n  __do_softirq+0x2c6/0x980 kernel/softirq.c:554\n  invoke_softirq kernel/softirq.c:428 [inline]\n  __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633\n  irq_exit_rcu+0x9/0x30 kernel/softirq.c:645\n  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]\n  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043\n  </IRQ>\n  <TASK>\n asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702\n RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758\n Code: 2b 00 74 08 4c 89 f7 e8 ba d1 84 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25\n RSP: 0018:ffffc90013657100 EFLAGS: 00000206\n RAX: 0000000000000001 RBX: 1ffff920026cae2c RCX: 0000000000000001\n RDX: dffffc0000000000 RSI: ffffffff8bcaca00 RDI: ffffffff8c1eaa60\n RBP: ffffc90013657260 R08: ffffffff92efe507 R09: 1ffffffff25dfca0\n R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: 1ffff920026cae28\n R13: dffffc0000000000 R14: ffffc90013657160 R15: 0000000000000246","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/3a7c1661ae1383364cd6092d851f5e5da64d476b","https://git.kernel.org/stable/c/4488617e5e995a09abe4d81add5fb165674edb59","https://git.kernel.org/stable/c/8ca9a750fc711911ef616ceb627d07357b04545e","https://git.kernel.org/stable/c/a2b01e65d9ba8af2bb086d3b7288ca53a07249ac","https://git.kernel.org/stable/c/e43dd2b1ec746e105b7db5f9ad6ef14685a615a4"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:00.836172422+00:00"},"epss":{"cve":"CVE-2024-36979","score":0.00257,"percentile":0.1737,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}