CVE-2023-53349 in Linux
Summary
by MITRE • 09/17/2025
In the Linux kernel, the following vulnerability has been resolved:
media: ov2740: Fix memleak in ov2740_init_controls()
There is a kmemleak when testing the media/i2c/ov2740.c with bpf mock device:
unreferenced object 0xffff8881090e19e0 (size 16): comm "51-i2c-ov2740", pid 278, jiffies 4294781584 (age 23.613s) hex dump (first 16 bytes): 00 f3 7c 0b 81 88 ff ff 80 75 6a 09 81 88 ff ff ..|......uj..... backtrace: [<000000004e9fad8f>] __kmalloc_node+0x44/0x1b0
[<0000000039c802f4>] kvmalloc_node+0x34/0x180
[<000000009b8b5c63>] v4l2_ctrl_handler_init_class+0x11d/0x180
[videodev]
[<0000000038644056>] ov2740_probe+0x37d/0x84f [ov2740]
[<0000000092489f59>] i2c_device_probe+0x28d/0x680
[<000000001038babe>] really_probe+0x17c/0x3f0
[<0000000098c7af1c>] __driver_probe_device+0xe3/0x170
[<00000000e1b3dc24>] device_driver_attach+0x34/0x80
[<000000005a04a34d>] bind_store+0x10b/0x1a0
[<00000000ce25d4f2>] drv_attr_store+0x49/0x70
[<000000007d9f4e9a>] sysfs_kf_write+0x8c/0xb0
[<00000000be6cff0f>] kernfs_fop_write_iter+0x216/0x2e0
[<0000000031ddb40a>] vfs_write+0x658/0x810
[<0000000041beecdd>] ksys_write+0xd6/0x1b0
[<0000000023755840>] do_syscall_64+0x38/0x90
[<00000000b2cc2da2>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
ov2740_init_controls() won't clean all the allocated resources in fail path, which may causes the memleaks. Add v4l2_ctrl_handler_free() to prevent memleak.
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Analysis
by VulDB Data Team • 12/27/2025
The vulnerability identified as CVE-2023-53349 represents a memory leak issue within the Linux kernel's media subsystem, specifically affecting the ov2740 camera driver. This flaw manifests during the initialization of camera controls where the driver fails to properly release allocated kernel memory resources when error conditions occur. The vulnerability was detected through testing with bpf mock devices and kmemleak analysis, which revealed unreferenced memory objects that remain allocated even after the driver initialization process encounters failures. The affected code path begins in the ov2740_init_controls() function and extends through the v4l2 control handler initialization process, ultimately leading to memory allocation that is never freed.
The technical root cause of this memory leak stems from improper resource management within the driver's error handling path. When the ov2740_probe function encounters issues during control initialization, it fails to invoke the v4l2_ctrl_handler_free() cleanup function to release previously allocated control handler resources. This creates a scenario where kernel memory allocated through the v4l2_ctrl_handler_init_class() function remains in use but becomes unreachable, effectively leaking 16 bytes of memory per failed initialization attempt. The backtrace shows the allocation occurring through kvmalloc_node and __kmalloc_node functions, indicating kernel memory allocation at the lowest level, while the call stack demonstrates how the failure propagates through the i2c device probing mechanism and driver binding process.
The operational impact of this vulnerability extends beyond simple memory consumption, potentially leading to system instability and performance degradation over time. While each individual memory leak is relatively small at 16 bytes, repeated initialization failures in embedded systems or high-throughput camera applications could accumulate to significant memory waste. The vulnerability affects systems running Linux kernels with the ov2740 driver, particularly those using media subsystem components for camera and video capture operations. This memory leak could be exploited in resource-constrained environments where memory exhaustion might occur through repeated driver initialization attempts, potentially leading to system crashes or degraded performance in camera subsystems.
The fix for this vulnerability involves adding a call to v4l2_ctrl_handler_free() within the error handling path of the ov2740_init_controls() function to ensure proper cleanup of allocated resources. This remediation follows established kernel development practices for resource management and aligns with the principle of releasing all allocated resources before function return, particularly in error conditions. The solution addresses the fundamental flaw in the driver's resource management by ensuring that when initialization fails, all previously allocated control handler memory is properly freed, preventing the accumulation of unreferenced kernel memory objects. This fix adheres to the CWE-401 principle of "Improper Release of Memory" and follows the ATT&CK technique T1484.001 "Privilege Abuse" by preventing potential denial of service through resource exhaustion. The patch demonstrates proper defensive programming practices and ensures that the driver maintains proper memory hygiene throughout its lifecycle, particularly during error conditions that may occur in real-world deployment scenarios involving camera hardware initialization failures.