CVE-2023-53814
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BaseFortify

Publication date: 2025-12-09

Last updated on: 2025-12-09

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: PCI: Fix dropping valid root bus resources with .end = zero On r8a7791/koelsch: kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) # cat /sys/kernel/debug/kmemleak unreferenced object 0xc3a34e00 (size 64): comm "swapper/0", pid 1, jiffies 4294937460 (age 199.080s) hex dump (first 32 bytes): b4 5d 81 f0 b4 5d 81 f0 c0 b0 a2 c3 00 00 00 00 .]...].......... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<fe3aa979>] __kmalloc+0xf0/0x140 [<34bd6bc0>] resource_list_create_entry+0x18/0x38 [<767046bc>] pci_add_resource_offset+0x20/0x68 [<b3f3edf2>] devm_of_pci_get_host_bridge_resources.constprop.0+0xb0/0x390 When coalescing two resources for a contiguous aperture, the second resource is enlarged to cover the full contiguous range, while the first resource is marked invalid. This invalidation is done by clearing the flags, start, and end members. When adding the initial resources to the bus later, invalid resources are skipped. Unfortunately, the check for an invalid resource considers only the end member, causing false positives. E.g. on r8a7791/koelsch, root bus resource 0 ("bus 00") is skipped, and no longer registered with pci_bus_insert_busn_res() (causing the memory leak), nor printed: pci-rcar-gen2 ee090000.pci: host bridge /soc/pci@ee090000 ranges: pci-rcar-gen2 ee090000.pci: MEM 0x00ee080000..0x00ee08ffff -> 0x00ee080000 pci-rcar-gen2 ee090000.pci: PCI: revision 11 pci-rcar-gen2 ee090000.pci: PCI host bridge to bus 0000:00 -pci_bus 0000:00: root bus resource [bus 00] pci_bus 0000:00: root bus resource [mem 0xee080000-0xee08ffff] Fix this by only skipping resources where all of the flags, start, and end members are zero.
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Meta Information
Published
2025-12-09
Last Modified
2025-12-09
Generated
2026-05-07
AI Q&A
2025-12-09
EPSS Evaluated
2026-05-05
NVD
CVE-2023-53814
EUVD
EUVD-2023-60092
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability in the Linux kernel involves improper handling of PCI root bus resources. When two resources are combined for a contiguous range, the first resource is incorrectly marked invalid by clearing its flags, start, and end members. Later, when adding resources to the bus, the check to skip invalid resources only looks at the 'end' member, causing valid resources to be mistakenly skipped. This leads to the root bus resource not being registered properly, which can cause issues such as memory leaks.


How can this vulnerability impact me? :

The vulnerability can cause valid root bus resources to be skipped and not registered with the PCI bus. This improper handling can lead to memory leaks and potentially disrupt the correct functioning of PCI devices on affected systems.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

You can detect this vulnerability by checking for suspected memory leaks reported by kmemleak in the Linux kernel. Use the command: cat /sys/kernel/debug/kmemleak to look for unreferenced objects that may indicate the issue.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, update the Linux kernel to a version where the fix is applied. The fix involves correcting the resource invalidation check to skip only resources where all flags, start, and end members are zero, preventing the skipping of valid root bus resources and associated memory leaks.


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