Description
In the Linux kernel, the following vulnerability has been resolved: can: hi311x: populate ndo_change_mtu() to prevent buffer overflow Sending an PF_PACKET allows to bypass the CAN framework logic and to directly reach the xmit() function of a CAN driver. The only check which is performed by the PF_PACKET framework is to make sure that skb->len fits the interface's MTU. Unfortunately, because the sun4i_can driver does not populate its net_device_ops->ndo_change_mtu(), it is possible for an attacker to configure an invalid MTU by doing, for example: $ ip link set can0 mtu 9999 After doing so, the attacker could open a PF_PACKET socket using the ETH_P_CANXL protocol: socket(PF_PACKET, SOCK_RAW, htons(ETH_P_CANXL)) to inject a malicious CAN XL frames. For example: struct canxl_frame frame = { .flags = 0xff, .len = 2048, }; The CAN drivers' xmit() function are calling can_dev_dropped_skb() to check that the skb is valid, unfortunately under above conditions, the malicious packet is able to go through can_dev_dropped_skb() checks: 1. the skb->protocol is set to ETH_P_CANXL which is valid (the function does not check the actual device capabilities). 2. the length is a valid CAN XL length. And so, hi3110_hard_start_xmit() receives a CAN XL frame which it is not able to correctly handle and will thus misinterpret it as a CAN frame. The driver will consume frame->len as-is with no further checks. This can result in a buffer overflow later on in hi3110_hw_tx() on this line: memcpy(buf + HI3110_FIFO_EXT_DATA_OFF, frame->data, frame->len); Here, frame->len corresponds to the flags field of the CAN XL frame. In our previous example, we set canxl_frame->flags to 0xff. Because the maximum expected length is 8, a buffer overflow of 247 bytes occurs! Populate net_device_ops->ndo_change_mtu() to ensure that the interface's MTU can not be set to anything bigger than CAN_MTU. By fixing the root cause, this prevents the buffer overflow.
Product status
57e83fb9b7468c75cb65cde1d23043553c346c6d before f2c247e9581024d8b3dd44cbe086bf2bebbef42c
57e83fb9b7468c75cb65cde1d23043553c346c6d before 8f351db6b2367991f0736b2cff082f5de4872113
57e83fb9b7468c75cb65cde1d23043553c346c6d before 7ab85762274c0fa997f0ef9a2307b2001aae43c4
57e83fb9b7468c75cb65cde1d23043553c346c6d before 57d332ce8c921d0e340650470bb0c1d707f216ee
57e83fb9b7468c75cb65cde1d23043553c346c6d before be1b25005fd0f9d4e78bec6695711ef87ee33398
57e83fb9b7468c75cb65cde1d23043553c346c6d before def814b4ba31b563584061d6895d5ff447d5bc14
57e83fb9b7468c75cb65cde1d23043553c346c6d before e77fdf9e33a83a08f04ab0cb68c19ddb365a622f
57e83fb9b7468c75cb65cde1d23043553c346c6d before ac1c7656fa717f29fac3ea073af63f0b9919ec9a
4.12
Any version before 4.12
5.4.300
5.10.245
5.15.194
6.1.155
6.6.109
6.12.50
6.16.10
6.17
References
git.kernel.org/...c/f2c247e9581024d8b3dd44cbe086bf2bebbef42c
git.kernel.org/...c/8f351db6b2367991f0736b2cff082f5de4872113
git.kernel.org/...c/7ab85762274c0fa997f0ef9a2307b2001aae43c4
git.kernel.org/...c/57d332ce8c921d0e340650470bb0c1d707f216ee
git.kernel.org/...c/be1b25005fd0f9d4e78bec6695711ef87ee33398
git.kernel.org/...c/def814b4ba31b563584061d6895d5ff447d5bc14
git.kernel.org/...c/e77fdf9e33a83a08f04ab0cb68c19ddb365a622f
git.kernel.org/...c/ac1c7656fa717f29fac3ea073af63f0b9919ec9a
