CVE-2021-47269
What it is
In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: ep0: fix NULL pointer exception There is no validation of the index from dwc3_wIndex_to_dep() and we might be referring a non-existing ep and trigger a NULL pointer exception. In certain configurations we might use fewer eps and the index might wrongly indicate a larger ep index than existing. By adding this validation from the patch we can actually report a wrong index back to the caller. In our usecase we are using a composite device on an older kernel, but upstream might use this fix also. Unfortunately, I cannot describe the hardware for others to reproduce the issue as it is a proprietary implementation. [ 82.958261] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a4 [ 82.966891] Mem abort info: [ 82.969663] ESR = 0x96000006 [ 82.972703] Exception class = DABT (current EL), IL = 32 bits [ 82.978603] SET = 0, FnV = 0 [ 82.981642] EA = 0, S1PTW = 0 [ 82.984765] Data abort info: [ 82.987631] ISV = 0, ISS = 0x00000006 [ 82.991449] CM = 0, WnR = 0 [ 82.994409] user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c6210ccc [ 83.000999] [00000000000000a4] pgd=0000000053aa5003, pud=0000000053aa5003, pmd=0000000000000000 [ 83.009685] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 83.026433] Process irq/62-dwc3 (pid: 303, stack limit = 0x000000003985154c) [ 83.033470] CPU: 0 PID: 303 Comm: irq/62-dwc3 Not tainted 4.19.124 #1 [ 83.044836] pstate: 60000085 (nZCv daIf -PAN -UAO) [ 83.049628] pc : dwc3_ep0_handle_feature+0x414/0x43c [ 83.054558] lr : dwc3_ep0_interrupt+0x3b4/0xc94 ... [ 83.141788] Call trace: [ 83.144227] dwc3_ep0_handle_feature+0x414/0x43c [ 83.148823] dwc3_ep0_interrupt+0x3b4/0xc94 [ 83.181546] ---[ end trace aac6b5267d84c32f ]---
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-476 · NULL pointer dereference
- Record status
- Analyzed
Affected
- Linux Kernel < 4.4.273
- Linux Kernel < 4.9.273
- Linux Kernel < 4.14.237
- Linux Kernel < 4.19.195
- Linux Kernel < 5.4.126
- Linux Kernel < 5.10.44
- Linux Kernel < 5.12.11
- Linux Kernel 5.13
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-47269.md and follow it. Check whether this project is affected by CVE-2021-47269. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/366369b89bedd59b1425386e8d4a18a466e420e4
- https://git.kernel.org/stable/c/470403639114895e2697c766fbe17be8d0e9b67a
- https://git.kernel.org/stable/c/60156089f07e724e4dc8483702d5e1ede4522749
- https://git.kernel.org/stable/c/788755756dd4a6aba1de479fec20b0fa600e7f19
- https://git.kernel.org/stable/c/96b74a99d360235c24052f1d060e64ac53f43528
- https://git.kernel.org/stable/c/990dc90750772622d44ca2ea6652c521e6f67e16
- https://git.kernel.org/stable/c/bd551e7c85939de2182010273450bfa78c3742fc
- https://git.kernel.org/stable/c/d00889080ab60051627dab1d85831cd9db750e2a
- https://git.kernel.org/stable/c/366369b89bedd59b1425386e8d4a18a466e420e4
- https://git.kernel.org/stable/c/470403639114895e2697c766fbe17be8d0e9b67a
References
- https://git.kernel.org/stable/c/366369b89bedd59b1425386e8d4a18a466e420e4
- https://git.kernel.org/stable/c/470403639114895e2697c766fbe17be8d0e9b67a
- https://git.kernel.org/stable/c/60156089f07e724e4dc8483702d5e1ede4522749
- https://git.kernel.org/stable/c/788755756dd4a6aba1de479fec20b0fa600e7f19
- https://git.kernel.org/stable/c/96b74a99d360235c24052f1d060e64ac53f43528
- https://git.kernel.org/stable/c/990dc90750772622d44ca2ea6652c521e6f67e16
- https://git.kernel.org/stable/c/bd551e7c85939de2182010273450bfa78c3742fc
- https://git.kernel.org/stable/c/d00889080ab60051627dab1d85831cd9db750e2a
- https://git.kernel.org/stable/c/366369b89bedd59b1425386e8d4a18a466e420e4
- https://git.kernel.org/stable/c/470403639114895e2697c766fbe17be8d0e9b67a
- https://git.kernel.org/stable/c/60156089f07e724e4dc8483702d5e1ede4522749
- https://git.kernel.org/stable/c/788755756dd4a6aba1de479fec20b0fa600e7f19
- https://git.kernel.org/stable/c/96b74a99d360235c24052f1d060e64ac53f43528
- https://git.kernel.org/stable/c/990dc90750772622d44ca2ea6652c521e6f67e16
- https://git.kernel.org/stable/c/bd551e7c85939de2182010273450bfa78c3742fc
- https://git.kernel.org/stable/c/d00889080ab60051627dab1d85831cd9db750e2a