Linux Kernel
CVE-2024-36979
HIGH
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
1DescriptionNVD
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: mst: fix vlan use-after-free
syzbot reported a suspicious rcu usage[1] in bridge's mst code. While fixing it I noticed that nothing prevents a vlan to be freed while walking the list from the same path (br forward delay timer). Fix the rcu usage and also make sure we are not accessing freed memory by making br_mst_vlan_set_state use rcu read lock.
[1] WARNING: suspicious RCU usage 6.9.0-rc6-syzkaller #0 Not tainted ----------------------------- net/bridge/br_private.h:1599 suspicious rcu_dereference_protected() usage! ... stack backtrace: CPU: 1 PID: 8017 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712 nbp_vlan_group net/bridge/br_private.h:1599 [inline] br_mst_set_state+0x1ea/0x650 net/bridge/br_mst.c:105 br_set_state+0x28a/0x7b0 net/bridge/br_stp.c:47 br_forward_delay_timer_expired+0x176/0x440 net/bridge/br_stp_timer.c:88 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2429 run_timer_base kernel/time/timer.c:2438 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 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 RSP: 0018:ffffc90013657100 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920026cae2c RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca00 RDI: ffffffff8c1eaa60 RBP: ffffc90013657260 R08: ffffffff92efe507 R09: 1ffffffff25dfca0 R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: 1ffff920026cae28 R13: dffffc0000000000 R14: ffffc90013657160 R15: 0000000000000246
AnalysisAI
In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: fix vlan use-after-free syzbot reported a suspicious rcu usage[1] in bridge's mst code. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Use After Free vulnerability could allow attackers to access freed memory to execute arbitrary code or crash the application.
Technical ContextAI
This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: fix vlan use-after-free syzbot reported a suspicious rcu usage[1] in bridge's mst code. While fixing it I noticed that nothing prevents a vlan to be freed while walking the list from the same path (br forward delay timer). Fix the rcu usage and also make sure we are not accessing freed memory by making br_mst_vlan_set_state use rcu read lock. [1] WARNING: suspicious RCU usage 6.9.0-rc6-syzkaller #0 Not tainted ----------------------------- net/bridge/br_private.h:1599 suspicious rcu_dereference_protected() usage! ... stack backtrace: CPU: 1 PID: 8017 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712 nbp_vlan_group net/bridge/br_private.h:1599 [inline] br_mst_set_state+0x1ea/0x650 net/bridge/br_mst.c:105 br_set_state+0x28a/0x7b0 net/bridge/br_stp.c:47 br_forward_delay_timer_expired+0x176/0x440 net/bridge/br_stp_timer.c:88 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2429 run_timer_base kernel/time/timer.c:2438 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 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 RSP: 0018:ffffc90013657100 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920026cae2c RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca00 RDI: ffffffff8c1eaa60 RBP: ffffc90013657260 R08: ffffffff92efe507 R09: 1ffffffff25dfca0 R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: 1ffff920026cae28 R13: dffffc0000000000 R14: ffffc90013657160 R15: 0000000000000246 Affected products include: Linux Linux Kernel.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.
More in Linux Kernel
View allLinux kernel contains a flaw known as 'Dirty Pipe' where improper pipe buffer flag initialization allows unprivileged lo
The overlayfs implementation in the linux (aka Linux kernel) package before 3.19.0-21.21 in Ubuntu through 15.04 does no
The packet_set_ring function in net/packet/af_packet.c in the Linux kernel through 4.10.6 does not properly validate cer
The check_alu_op function in kernel/bpf/verifier.c in the Linux kernel through 4.4 allows local users to cause a denial
Linux kernel: Exploitable memory corruption due to UFO to non-UFO path switch. Rated high severity (CVSS 7.0). Public ex
The ovl_setattr function in fs/overlayfs/inode.c in the Linux kernel through 4.3.3 attempts to merge distinct setattr op
The mem_write function in the Linux kernel before 3.2.2, when ASLR is disabled, does not properly check permissions when
The compat_sys_recvmmsg function in net/compat.c in the Linux kernel before 3.13.2, when CONFIG_X86_X32 is enabled, allo
Race condition in net/packet/af_packet.c in the Linux kernel through 4.8.12 allows local users to gain privileges or cau
The join_session_keyring function in security/keys/process_keys.c in the Linux kernel before 4.4.1 mishandles object ref
A remote code execution vulnerability in the Broadcom Wi-Fi firmware could enable a remote attacker to execute arbitrary
It was discovered that the cls_route filter implementation in the Linux kernel would not remove an old filter from the h
Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
View allShare
External POC / Exploit Code
Leaving vuln.today