ghsa-355p-v6gf-92vj
Vulnerability from github
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:
{
"affected": [],
"aliases": [
"CVE-2024-36979"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-06-19T14:15:13Z",
"severity": "HIGH"
},
"details": "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\u0027s 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 \u003cIRQ\u003e\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 \u003c/IRQ\u003e\n \u003cTASK\u003e\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 \u003c4b\u003e 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",
"id": "GHSA-355p-v6gf-92vj",
"modified": "2024-08-26T15:31:13Z",
"published": "2024-06-19T15:30:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-36979"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3a7c1661ae1383364cd6092d851f5e5da64d476b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4488617e5e995a09abe4d81add5fb165674edb59"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8ca9a750fc711911ef616ceb627d07357b04545e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a2b01e65d9ba8af2bb086d3b7288ca53a07249ac"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e43dd2b1ec746e105b7db5f9ad6ef14685a615a4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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- Patched: This vulnerability was successfully patched by the user reporting the sighting.
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