--- id: CVE-2024-40980 title: |- In the Linux kernel, the following vulnerability has been resolved: drop_monitor: replace spin_lock by raw_spin_lock trace_drop_common() is called with preemption disabled, and it acquires a spin_lock summary: |- In the Linux kernel, the following vulnerability has been resolved: drop_monitor: replace spin_lock by raw_spin_lock trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernel… severity: high cvss: 7.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-667 vendor: linux product: linux_kernel affected: - linux_kernel < 5.4.279 - 'linux_kernel >= 5.5, < 5.10.221' - 'linux_kernel >= 5.11, < 5.15.162' - 'linux_kernel >= 5.16, < 6.1.96' - 'linux_kernel >= 6.2, < 6.6.36' - 'linux_kernel >= 6.7, < 6.9.7' patched: - linux_kernel 6.9.7 published: '2024-07-12' updated: '2026-10-15' sourceUpdated: '2026-10-15T01:18:39.740' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-40980' references: - url: 'https://git.kernel.org/stable/c/07ea878684dfb78a9d4f564c39d07e855a9e242e' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/594e47957f3fe034645e6885393ce96c12286334' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/76ce2f9125244e1708d29c1d3f9d1d50b347bda0' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/96941f29ebcc1e9cbf570dc903f30374909562f5' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/b3722fb69468693555f531cddda5c30444726dac' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/f1e197a665c2148ebc25fe09c53689e60afea195' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/f251ccef1d864790e5253386e95544420b7cd8f3' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/07ea878684dfb78a9d4f564c39d07e855a9e242e' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/594e47957f3fe034645e6885393ce96c12286334' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/76ce2f9125244e1708d29c1d3f9d1d50b347bda0' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/96941f29ebcc1e9cbf570dc903f30374909562f5' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/b3722fb69468693555f531cddda5c30444726dac' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/f1e197a665c2148ebc25fe09c53689e60afea195' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/f251ccef1d864790e5253386e95544420b7cd8f3' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-355557.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-613116.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e tags: - nvd - cve.org epss: 0.00757 epssPercentile: 0.54974 ingestedAt: '2026-10-15T03:30:12.724Z' ssvc: exploitation: none automatable: 'no' technicalImpact: partial timestamp: '2024-09-10T17:02:23.500077Z' --- ## Overview In the Linux kernel, the following vulnerability has been resolved: drop_monitor: replace spin_lock by raw_spin_lock trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 #1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 #2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 #3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 #4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ #7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context. ## Affected - `linux_kernel < 5.4.279` - `linux_kernel >= 5.5, < 5.10.221` - `linux_kernel >= 5.11, < 5.15.162` - `linux_kernel >= 5.16, < 6.1.96` - `linux_kernel >= 6.2, < 6.6.36` - `linux_kernel >= 6.7, < 6.9.7` ## Remediation Upgrade past the affected range: - `linux_kernel 6.9.7`