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CVE-2022-49006— tracing: Free buffers when a used dynamic event is removed

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tracing子系统中动态事件移除后缓冲区未释放的问题,可能导致内核崩溃。

AI Predicted 7.8 Difficulty: Hard EPSS 0.26% · P16

Affected Version Matrix 12

VendorProduct Version RangeStatus
Linux Linux 77b44d1b7c28360910cdbd427fb62d485c08674c< 1603feac154ff38514e8354e3079a455eb4801e2 affected
77b44d1b7c28360910cdbd427fb62d485c08674c< be111ebd8868d4b7c041cb3c6102e1ae27d6dc1d affected
77b44d1b7c28360910cdbd427fb62d485c08674c< 417d5ea6e735e5d88ffb6c436cf2938f3f476dd1 affected
77b44d1b7c28360910cdbd427fb62d485c08674c< c52d0c8c4f38f7580cff61c4dfe1034c580cedfd affected
77b44d1b7c28360910cdbd427fb62d485c08674c< 4313e5a613049dfc1819a6dfb5f94cf2caff9452 affected
2.6.33 affected
< 2.6.33 unaffected
5.4.226≤ 5.4.* unaffected
… +4 more rows
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I. Basic Information for CVE-2022-49006

Vulnerability Information

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Vulnerability Title
tracing: Free buffers when a used dynamic event is removed
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: tracing: Free buffers when a used dynamic event is removed After 65536 dynamic events have been added and removed, the "type" field of the event then uses the first type number that is available (not currently used by other events). A type number is the identifier of the binary blobs in the tracing ring buffer (known as events) to map them to logic that can parse the binary blob. The issue is that if a dynamic event (like a kprobe event) is traced and is in the ring buffer, and then that event is removed (because it is dynamic, which means it can be created and destroyed), if another dynamic event is created that has the same number that new event's logic on parsing the binary blob will be used. To show how this can be an issue, the following can crash the kernel: # cd /sys/kernel/tracing # for i in `seq 65536`; do echo 'p:kprobes/foo do_sys_openat2 $arg1:u32' > kprobe_events # done For every iteration of the above, the writing to the kprobe_events will remove the old event and create a new one (with the same format) and increase the type number to the next available on until the type number reaches over 65535 which is the max number for the 16 bit type. After it reaches that number, the logic to allocate a new number simply looks for the next available number. When an dynamic event is removed, that number is then available to be reused by the next dynamic event created. That is, once the above reaches the max number, the number assigned to the event in that loop will remain the same. Now that means deleting one dynamic event and created another will reuse the previous events type number. This is where bad things can happen. After the above loop finishes, the kprobes/foo event which reads the do_sys_openat2 function call's first parameter as an integer. # echo 1 > kprobes/foo/enable # cat /etc/passwd > /dev/null # cat trace cat-2211 [005] .... 2007.849603: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849620: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849838: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849880: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196 # echo 0 > kprobes/foo/enable Now if we delete the kprobe and create a new one that reads a string: # echo 'p:kprobes/foo do_sys_openat2 +0($arg2):string' > kprobe_events And now we can the trace: # cat trace sendmail-1942 [002] ..... 530.136320: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930817: foo: (do_sys_openat2+0x0/0x240) arg1="������������������������������������������������������������������������������������������������" cat-2046 [004] ..... 530.930961: foo: (do_sys_openat2+0x0/0x240) arg1="������������������������������������������������������������������������������������������������" cat-2046 [004] ..... 530.934278: foo: (do_sys_openat2+0x0/0x240) arg1="������������������������������������������������������������������������������������������������" cat-2046 [004] ..... 530.934563: foo: (do_sys_openat2+0x0/0x240) arg1="��������������������������������������� ---truncated---
Source: CVE Program / CVE List V5
CVSS Information
N/A
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tracing子系统中动态事件移除后缓冲区未释放的问题,可能导致内核崩溃。
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 77b44d1b7c28360910cdbd427fb62d485c08674c ~ 1603feac154ff38514e8354e3079a455eb4801e2 -
Linux Linux 2.6.33 -

II. Public POCs for CVE-2022-49006

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III. Intelligence Information for CVE-2022-49006

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Patches & Fixes for CVE-2022-49006 (5)

Same Patch Batch · Linux · 2024-10-21 · 372 CVEs total

CVE-2024-50033 9.8 CRITICAL slip: make slhc_remember() more robust against malicious packets
CVE-2024-49855 9.8 CRITICAL nbd: fix race between timeout and normal completion
CVE-2024-47695 9.8 CRITICAL RDMA/rtrs-clt: Reset cid to con_num - 1 to stay in bounds
CVE-2022-48985 9.8 CRITICAL net: mana: Fix race on per-CQ variable napi work_done
CVE-2022-49003 9.8 CRITICAL nvme: fix SRCU protection of nvme_ns_head list
CVE-2024-50043 9.8 CRITICAL nfsd: fix possible badness in FREE_STATEID
CVE-2024-50047 9.8 CRITICAL smb: client: fix UAF in async decryption
CVE-2024-50046 9.8 CRITICAL NFSv4: Prevent NULL-pointer dereference in nfs42_complete_copies()
CVE-2024-49996 9.4 CRITICAL cifs: Fix buffer overflow when parsing NFS reparse points
CVE-2024-47678 9.4 CRITICAL icmp: change the order of rate limits
CVE-2022-48962 8.8 HIGH net: hisilicon: Fix potential use-after-free in hisi_femac_rx()
CVE-2024-49950 8.8 HIGH Bluetooth: L2CAP: Fix uaf in l2cap_connect
CVE-2024-49939 8.8 HIGH wifi: rtw89: avoid to add interface to list twice when SER
CVE-2022-48967 8.8 HIGH NFC: nci: Bounds check struct nfc_target arrays
CVE-2022-48964 8.8 HIGH ravb: Fix potential use-after-free in ravb_rx_gbeth()
CVE-2024-50029 8.8 HIGH Bluetooth: hci_conn: Fix UAF in hci_enhanced_setup_sync
CVE-2024-49930 8.8 HIGH wifi: ath11k: fix array out-of-bound access in SoC stats
CVE-2024-50041 8.8 HIGH i40e: Fix macvlan leak by synchronizing access to mac_filter_hash
CVE-2024-49936 8.8 HIGH net/xen-netback: prevent UAF in xenvif_flush_hash()
CVE-2022-48954 8.8 HIGH s390/qeth: fix use-after-free in hsci

Showing top 20 of 372 CVEs. View all on vendor page &rarr; →

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