CVE-2026-89891
media: em28xx: fix use-after-free of dev_next->devlist on disconnect
Description
In the Linux kernel, the following vulnerability has been resolved: media: em28xx: fix use-after-free of dev_next->devlist on disconnect When a device with has_dual_ts=1 is probed and the is_audio_only path is taken, both dev and dev->dev_next are added to the global em28xx_devlist via em28xx_init_extension(). However, during disconnect, em28xx_close_extension(dev) only calls list_del(&dev->devlist), leaving dev->dev_next->devlist still linked in the global list. When dev_next is subsequently freed via kref_put(), its devlist entry becomes a dangling pointer in em28xx_devlist. The next device probe that calls em28xx_init_extension() triggers a list corruption BUG when list_add_tail detects the freed node. This bug was exposed by commit a368ecde8a50 ("USB: core: Fix duplicate endpoint bug by clearing reserved bits in the descriptor") which clears reserved bits in bEndpointAddress during endpoint parsing. This causes fuzzed endpoint addresses like 0xf3 to be normalized to 0x83, which em28xx interprets as a vendor audio endpoint, enabling the is_audio_only + has_dual_ts code path that was previously unreachable with such descriptors. Fix this by removing dev->dev_next->devlist from the global list in em28xx_close_extension() before the device is freed.
INFO
Published Date :
Sept. 16, 2026, 11:16 a.m.
Last Modified :
Sept. 16, 2026, 11:16 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Ensure dev->dev_next->devlist is removed from global list.
- Update the Linux kernel to include the fix.
- Apply the relevant patch for em28xx driver.
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associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 16, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: media: em28xx: fix use-after-free of dev_next->devlist on disconnect When a device with has_dual_ts=1 is probed and the is_audio_only path is taken, both dev and dev->dev_next are added to the global em28xx_devlist via em28xx_init_extension(). However, during disconnect, em28xx_close_extension(dev) only calls list_del(&dev->devlist), leaving dev->dev_next->devlist still linked in the global list. When dev_next is subsequently freed via kref_put(), its devlist entry becomes a dangling pointer in em28xx_devlist. The next device probe that calls em28xx_init_extension() triggers a list corruption BUG when list_add_tail detects the freed node. This bug was exposed by commit a368ecde8a50 ("USB: core: Fix duplicate endpoint bug by clearing reserved bits in the descriptor") which clears reserved bits in bEndpointAddress during endpoint parsing. This causes fuzzed endpoint addresses like 0xf3 to be normalized to 0x83, which em28xx interprets as a vendor audio endpoint, enabling the is_audio_only + has_dual_ts code path that was previously unreachable with such descriptors. Fix this by removing dev->dev_next->devlist from the global list in em28xx_close_extension() before the device is freed. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89891.json">CVE-2026-89891</a> Added Reference https://git.kernel.org/stable/c/0782807552b6aff41b4656c6c9076a3231d3e79d Added Reference https://git.kernel.org/stable/c/16cb1ee17e093175b4d9ae33202f68e5b108cca2 Added Reference https://git.kernel.org/stable/c/1ed575b1991f68569eb589b7747d3bc26aa6a8a2 Added Reference https://git.kernel.org/stable/c/20aacd87550be297dc39a3f9532dcfff91586510 Added Reference https://git.kernel.org/stable/c/20c2c65f3d9f7c278dc9750531d3201ac8bf78b7 Added Reference https://git.kernel.org/stable/c/826915b6b65e2d3251e7248ea54289a22d748c84 Added Reference https://git.kernel.org/stable/c/da4b07da6281e39ce4c01e1227e036f3bf600e14 Added Reference https://git.kernel.org/stable/c/f61720346fdcc1a2deec59a2f6cbb0cc20d1dc18