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CVE-2024-40947— ima: Avoid blocking in RCU read-side critical section

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel 存在安全漏洞，该漏洞源于 ima 组件在 RCU 读取关键部分中存在阻塞调用问题。

CVSS 7.8 · High EPSS 0.26% · P17

Possible ATT&CK Techniques 1 AI

T1211 · Exploitation for Stealth

Affected Version Matrix 21

VendorProduct Version RangeStatus
Linux Linux c4b035b1f036ddd53fbfced49046e586c5ad8a3e< a6176a802c4bfb83bf7524591aa75f44a639a853 affected
2d4bc60693c4206c64723e94ae5f7a04c0b8f18f< a38e02265c681b51997a264aaf743095e2ee400a affected
8008f1691c15f353f5a53dc5d450b8262cb57421< 9c3906c3738562b1fedc6f1cfc81756a7cfefff0 affected
c7423dbdbc9ecef7fff5239d144cad4b9887f4de< 28d0ecc52f6c927d0e9ba70a4f2c1ea15453ee88 affected
c7423dbdbc9ecef7fff5239d144cad4b9887f4de< 58275455893066149e9f4df2223ab2fdbdc59f9c affected
c7423dbdbc9ecef7fff5239d144cad4b9887f4de< 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 affected
38d48fd224036717fcb3437e7af1314f6ebcd2d0 affected
69c60b2a2dbb4887739d3a13297cc0dae3793f35 affected
… +13 more rows
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I. Basic Information for CVE-2024-40947

Vulnerability Information
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Vulnerability Title
ima: Avoid blocking in RCU read-side critical section
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ima: Avoid blocking in RCU read-side critical section A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel 存在安全漏洞，该漏洞源于 ima 组件在 RCU 读取关键部分中存在阻塞调用问题。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux c4b035b1f036ddd53fbfced49046e586c5ad8a3e ~ a6176a802c4bfb83bf7524591aa75f44a639a853 -
Linux Linux 6.2 -

II. Public POCs for CVE-2024-40947

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III. Intelligence Information for CVE-2024-40947

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Other References for CVE-2024-40947 (6)

Same Patch Batch · Linux · 2024-07-12 · 122 CVEs total

CVE-2024-40937 9.8 CRITICAL gve: Clear napi->skb before dev_kfree_skb_any()
CVE-2024-40907 9.8 CRITICAL ionic: fix kernel panic in XDP_TX action
CVE-2024-40999 9.8 CRITICAL net: ena: Add validation for completion descriptors consistency
CVE-2024-40923 9.8 CRITICAL vmxnet3: disable rx data ring on dma allocation failure
CVE-2024-40983 9.8 CRITICAL tipc: force a dst refcount before doing decryption
CVE-2024-40910 8.8 HIGH ax25: Fix refcount imbalance on inbound connections
CVE-2024-40911 8.8 HIGH wifi: cfg80211: Lock wiphy in cfg80211_get_station
CVE-2024-40941 8.1 HIGH wifi: iwlwifi: mvm: don't read past the mfuart notifcation
CVE-2024-40953 7.9 HIGH KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin()
CVE-2024-40918 7.8 HIGH parisc: Try to fix random segmentation faults in package builds
CVE-2024-39495 7.8 HIGH greybus: Fix use-after-free bug in gb_interface_release due to race condition.
CVE-2024-40909 7.8 HIGH bpf: Fix a potential use-after-free in bpf_link_free()
CVE-2024-40991 7.8 HIGH dmaengine: ti: k3-udma-glue: Fix of_k3_udma_glue_parse_chn_by_id()
CVE-2024-40990 7.8 HIGH RDMA/mlx5: Add check for srq max_sge attribute
CVE-2024-40989 7.8 HIGH KVM: arm64: Disassociate vcpus from redistributor region on teardown
CVE-2024-40925 7.8 HIGH block: fix request.queuelist usage in flush
CVE-2024-40984 7.8 HIGH ACPICA: Revert "ACPICA: avoid Info: mapping multiple BARs. Your kernel is fine."
CVE-2024-40924 7.8 HIGH drm/i915/dpt: Make DPT object unshrinkable
CVE-2024-40970 7.8 HIGH Avoid hw_desc array overrun in dw-axi-dmac
CVE-2024-40943 7.8 HIGH ocfs2: fix races between hole punching and AIO+DIO

Showing top 20 of 122 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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