usb: dwc3: gadget: check that event count does not exceed event buffer length

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: check that event count does not exceed event buffer length The event count is read from register DWC3_GEVNTCOUNT. There is a check for the count being zero, but not for exceeding the event buffer length. Check that event count does not exceed event buffer length, avoiding an out-of-bounds access when memcpy'ing the event. Crash log: Unable to handle kernel paging request at virtual address ffffffc0129be000 pc : __memcpy+0x114/0x180 lr : dwc3_check_event_buf+0xec/0x348 x3 : 0000000000000030 x2 : 000000000000dfc4 x1 : ffffffc0129be000 x0 : ffffff87aad60080 Call trace: __memcpy+0x114/0x180 dwc3_interrupt+0x24/0x34

References

• https://git.kernel.org/stable/c/015c39f38e69a491d2abd5e98869a500a9459b3b
• https://git.kernel.org/stable/c/b43225948b231b3f331194010f84512bee4d9f59
• https://git.kernel.org/stable/c/c0079630f268843a25ed75226169cba40e0d8880
• https://git.kernel.org/stable/c/a44547015287a19001384fe94dbff84c92ce4ee1
• https://git.kernel.org/stable/c/c4d80e41cb42008dceb35e5dbf52574d93beac0d
• https://git.kernel.org/stable/c/52a7c9d930b95aa8b1620edaba4818040c32631f
• https://git.kernel.org/stable/c/99d655119b870ee60e4dbf310aa9a1ed8d9ede3d
• https://git.kernel.org/stable/c/63ccd26cd1f6600421795f6ca3e625076be06c9f