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CVE-2022-49085

HIGHCVSS 7.8/10EPSS 0.26%

Last modified

CVE-2022-49085 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: drbd: Fix five use after free bugs in get_initial_state In get_initial_state, it calls notify_initial_state_done(skb,..) if cb->args[5]==1. If genlmsg_put() failed in notify_initial_state_done(), the skb will be freed by nlmsg_free(skb). Then get_initial_state will goto out and the freed skb will be used by return value skb->len, which is a uaf bug. What's worse, the same problem goes even further: skb can also be freed in the notify_*_state_change -> notify_*_state calls below. Thus 4 additional uaf bugs happened. My patch lets the problem callee functions: notify_initial_state_done and notify_*_state_change return an error code if errors happen. So that the error codes could be propagated and the uaf bugs can be avoid. v2 reports a compilation warning. EPSS estimates a 0.26% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: drbd: Fix five use after free bugs in get_initial_state In get_initial_state, it calls notify_initial_state_done(skb,..) if cb->args[5]==1. If genlmsg_put() failed in notify_initial_state_done(), the skb will be freed by nlmsg_free(skb). Then get_initial_state will goto out and the freed skb will be used by return value skb->len, which is a uaf bug. What's worse, the same problem goes even further: skb can also be freed in the notify_*_state_change -> notify_*_state calls below. Thus 4 additional uaf bugs happened. My patch lets the problem callee functions: notify_initial_state_done and notify_*_state_change return an error code if errors happen. So that the error codes could be propagated and the uaf bugs can be avoid. v2 reports a compilation warning. This v3 fixed this warning and built successfully in my local environment with no additional warnings. v2: https://lore.kernel.org/patchwork/patch/1435218/

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.26%

17.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 4.5, < 4.9.311—
LinuxLinux Kernel>= 4.10, < 4.14.276—
LinuxLinux Kernel>= 4.15, < 4.19.238—
LinuxLinux Kernel>= 4.20, < 5.4.189—
LinuxLinux Kernel>= 5.5, < 5.10.111—
LinuxLinux Kernel>= 5.11, < 5.15.34—
LinuxLinux Kernel>= 5.16, < 5.16.20—
LinuxLinux Kernel>= 5.17, < 5.17.3—
LinuxLinux Kernel5.18Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2022-49085?
In the Linux kernel, the following vulnerability has been resolved: drbd: Fix five use after free bugs in get_initial_state In get_initial_state, it calls notify_initial_state_done(skb,..) if cb->args[5]==1. If genlmsg_put() failed in notify_initial_state_done(), the skb will be freed by nlmsg_free(skb). Then get_initial_state will goto out and the freed skb will be used by return value skb->len, which is a uaf bug. What's worse, the same problem goes even further: skb can also be freed in the notify_*_state_change -> notify_*_state calls below. Thus 4 additional uaf bugs happened. My patch lets the problem callee functions: notify_initial_state_done and notify_*_state_change return an error code if errors happen. So that the error codes could be propagated and the uaf bugs can be avoid. v2 reports a compilation warning. This v3 fixed this warning and built successfully in my local environment with no additional warnings. v2: https://lore.kernel.org/patchwork/patch/1435218/
How severe is CVE-2022-49085?
CVE-2022-49085 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.
How do I fix CVE-2022-49085?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST