Linux xhci driver NULL pointer deref fix in usb_ep0_reinit

From this webpage screenshot, the following key information about the vulnerability can be obtained: 1. Vulnerability Description: - Title: xhci: Fix Panther point NULL pointer deref at full-speed re-enumeration - Description: Fixes a NULL pointer dereference issue in Panther point during full-speed re-enumeration. When re-enumerating full-speed devices, the maximum packet size for endpoint 0 may need to be reconfigured. The USB core calls in this case, which leads to calling . 2. Context of the Issue: - Device Behavior: During re-enumeration of full-speed devices, if the address device command fails, a new structure is allocated, but the bandwidth table pointer is not properly set. - Trigger Condition: This results in a NULL pointer dereference when attempts to check and reserve bandwidth during the next call to . 3. Fix Implemented: - Code Modification: Ensures the bandwidth table pointer is correctly set after a failed address device command, and avoids bandwidth checking when no actual endpoint exists. - Code Snippet: 4. Reporting and Fixing: - Reporter: Karel Balej - Fixers: Mathias Nyman and Greg Kroah-Hartman - Related Link: https://lore.kernel.org/linux-usb/D3CKQQAETH47.1MUO22RTCH2O3@matfyz.cz/ 5. Patch Application: - Patch Location: - Patch Content: The code snippet shows the modified function, which includes added condition checks and bandwidth reservation logic. This information indicates that the vulnerability relates to bandwidth management during the re-enumeration of USB full-speed devices. The fix involves modifying the function to ensure proper setting of the bandwidth table pointer and conditional bandwidth checking.

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Linux xhci driver NULL pointer deref fix in usb_ep0_reinit