CVE-2026-68224 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
media: mali-c55: Fix possible ERR_PTR in enable_streams
The media_pad_remote_pad_unique() function returns either a valid pointer or an ERR_PTR() on failure (-ENOTUNIQ if multiple links are enabled, -ENOLINK if no connected pad is found). The return value was assigned directly to isp->remote_src and dereferenced in the next line without checking for errors, which could lead to an ERR_PTR dereference.
Add proper error checking with IS_ERR() before dereferencing the pointer. Also set isp->remote_src to NULL on error to maintain consistency with other error paths in the function.
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Analysis
by VulDB Data Team • 08/11/2026
The vulnerability identified in the linux kernel's media subsystem represents a critical error handling flaw in the mali-c55 driver that could lead to system instability and potential privilege escalation. This issue stems from improper validation of function return values within the enable_streams functionality, specifically concerning the media_pad_remote_pad_unique() function which is responsible for identifying remote source pads in media device configurations. The flaw manifests when the function returns error pointers through ERR_PTR() macro encapsulation rather than valid memory addresses, yet these error conditions are not properly evaluated before subsequent pointer dereference operations.
The technical implementation of this vulnerability occurs at the kernel level where the isp->remote_src variable receives a direct assignment from media_pad_remote_pad_unique() without appropriate error validation. When this function encounters multiple links or no connected pads, it returns specific error codes wrapped in ERR_PTR() format such as -ENOTUNIQ for multiple connections or -ENOLINK for missing connections. The absence of IS_ERR() checks before dereferencing these values creates a path where kernel code attempts to access memory locations that are actually error indicators rather than valid pointers, potentially causing kernel panics or undefined behavior.
The operational impact of this vulnerability extends beyond simple system crashes to encompass potential security implications within embedded media processing environments. In automotive or industrial applications utilizing mali-c55 video processors, such a flaw could enable malicious actors to destabilize critical systems through carefully crafted media stream configurations. The inconsistency in error handling paths within the function means that while some code paths properly set isp->remote_src to NULL on failure, others leave it in an invalid state, creating unpredictable behavior that could be exploited by attackers to gain elevated privileges or cause denial of service conditions.
Security implications align with CWE-476 which addresses null pointer dereference vulnerabilities, and the flaw demonstrates characteristics consistent with ATT&CK technique T1068 which involves exploitation of privilege escalation opportunities. The vulnerability affects systems where the mali-c55 driver is utilized for video processing, particularly in mobile devices or embedded systems running linux kernels. Proper mitigation requires implementing comprehensive error checking using IS_ERR() macro validation before any pointer dereference operations. Additionally, setting isp->remote_src to NULL on error conditions ensures consistent state management across all error paths and prevents potential cascading failures that could occur from leaving variables in invalid states. The fix addresses both immediate safety concerns through proper validation and long-term system stability by maintaining consistent error handling patterns throughout the driver codebase.
This vulnerability highlights the critical importance of robust error handling in kernel space programming where improper validation can lead to system-wide failures. The patch demonstrates essential defensive programming practices that should be applied universally across kernel drivers, particularly those handling hardware abstraction layers where multiple failure modes exist. The resolution ensures that all error conditions are properly evaluated and handled before any subsequent processing occurs, maintaining system integrity while preventing potential exploitation of the error path for malicious purposes.