Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2024-50220— fork: do not invoke uffd on fork if error occurs

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，该漏洞源于存在错误发生时uffd调用问题。

AI Predicted 3.3 Difficulty: Moderate EPSS 0.17% · P6

Possible ATT&CK Techniques 1 AI

T1055 · Process Injection

Affected Version Matrix 6

VendorProduct Version RangeStatus
Linux Linux d2406291483775ecddaee929231a39c70c08fda2< 92b472945dbf8abc020e9259c0088026f7027dfc affected
d2406291483775ecddaee929231a39c70c08fda2< f64e67e5d3a45a4a04286c47afade4b518acd47b affected
6.8 affected
< 6.8 unaffected
6.11.7≤ 6.11.* unaffected
6.12≤ * unaffected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2024-50220

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
fork: do not invoke uffd on fork if error occurs
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: fork: do not invoke uffd on fork if error occurs Patch series "fork: do not expose incomplete mm on fork". During fork we may place the virtual memory address space into an inconsistent state before the fork operation is complete. In addition, we may encounter an error during the fork operation that indicates that the virtual memory address space is invalidated. As a result, we should not be exposing it in any way to external machinery that might interact with the mm or VMAs, machinery that is not designed to deal with incomplete state. We specifically update the fork logic to defer khugepaged and ksm to the end of the operation and only to be invoked if no error arose, and disallow uffd from observing fork events should an error have occurred. This patch (of 2): Currently on fork we expose the virtual address space of a process to userland unconditionally if uffd is registered in VMAs, regardless of whether an error arose in the fork. This is performed in dup_userfaultfd_complete() which is invoked unconditionally, and performs two duties - invoking registered handlers for the UFFD_EVENT_FORK event via dup_fctx(), and clearing down userfaultfd_fork_ctx objects established in dup_userfaultfd(). This is problematic, because the virtual address space may not yet be correctly initialised if an error arose. The change in commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") makes this more pertinent as we may be in a state where entries in the maple tree are not yet consistent. We address this by, on fork error, ensuring that we roll back state that we would otherwise expect to clean up through the event being handled by userland and perform the memory freeing duty otherwise performed by dup_userfaultfd_complete(). We do this by implementing a new function, dup_userfaultfd_fail(), which performs the same loop, only decrementing reference counts. Note that we perform mmgrab() on the parent and child mm's, however userfaultfd_ctx_put() will mmdrop() this once the reference count drops to zero, so we will avoid memory leaks correctly here.
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，该漏洞源于存在错误发生时uffd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 d2406291483775ecddaee929231a39c70c08fda2 ~ 92b472945dbf8abc020e9259c0088026f7027dfc -
Linux Linux 6.8 -

II. Public POCs for CVE-2024-50220

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2024-50220

请登录查看更多情报信息。

Patches & Fixes for CVE-2024-50220 (2)

Vendor Advisories for CVE-2024-50220 (1)

Same Patch Batch · Linux · 2024-11-09 · 49 CVEs total

CVE-2024-50215 8.1 HIGH nvmet-auth: assign dh_key to NULL after kfree_sensitive
CVE-2024-50225 7.8 HIGH btrfs: fix error propagation of split bios
CVE-2024-50217 7.8 HIGH btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()
CVE-2024-50221 7.8 HIGH drm/amd/pm: Vangogh: Fix kernel memory out of bounds write
CVE-2024-50262 7.8 HIGH bpf: Fix out-of-bounds write in trie_get_next_key()
CVE-2024-50261 7.8 HIGH macsec: Fix use-after-free while sending the offloading packet
CVE-2024-50246 7.8 HIGH fs/ntfs3: Add rough attr alloc_size check
CVE-2024-50230 7.8 HIGH nilfs2: fix kernel bug due to missing clearing of checked flag
CVE-2024-50253 7.8 HIGH bpf: Check the validity of nr_words in bpf_iter_bits_new()
CVE-2024-50237 7.8 HIGH wifi: mac80211: do not pass a stopped vif to the driver in .get_txpower
CVE-2024-50250 7.8 HIGH fsdax: dax_unshare_iter needs to copy entire blocks
CVE-2024-50235 7.8 HIGH wifi: cfg80211: clear wdev->cqm_config pointer on free
CVE-2024-50256 7.5 HIGH netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()
CVE-2024-50241 7.5 HIGH NFSD: Initialize struct nfsd4_copy earlier
CVE-2024-50247 7.3 HIGH fs/ntfs3: Check if more than chunk-size bytes are written
CVE-2024-50248 7.1 HIGH ntfs3: Add bounds checking to mi_enum_attr()
CVE-2024-50257 7.0 HIGH netfilter: Fix use-after-free in get_info()
CVE-2024-50222 7.0 HIGH iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP
CVE-2024-50245 fs/ntfs3: Fix possible deadlock in mi_read
CVE-2024-50239 phy: qcom: qmp-usb-legacy: fix NULL-deref on runtime suspend

Showing top 20 of 49 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2024-50220

No comments yet

Leave a comment