55%
18%
60%
In the Linux kernel, the following vulnerability has been resolved: phy: ti: phy-omap-usb2: Fix NULL pointer dereference for SRP If the external phy working together with phy-omap-usb2 does not implement send_srp(), we may still attempt to call it. This can happen on an idle Ethernet gadget triggering a wakeup for example: configfs-gadget.g1 gadget.0: ECM Suspend configfs-gadget.g1 gadget.0: Port suspended. Triggering wakeup ... Unable to handle kernel NULL pointer dereference at virtual address 00000000 when execute ... PC is at 0x0 LR is at musb_gadget_wakeup+0x1d4/0x254 [musb_hdrc] ... musb_gadget_wakeup [musb_hdrc] from usb_gadget_wakeup+0x1c/0x3c [udc_core] usb_gadget_wakeup [udc_core] from eth_start_xmit+0x3b0/0x3d4 [u_ether] eth_start_xmit [u_ether] from dev_hard_start_xmit+0x94/0x24c dev_hard_start_xmit from sch_direct_xmit+0x104/0x2e4 sch_direct_xmit from __dev_queue_xmit+0x334/0xd88 __dev_queue_xmit from arp_solicit+0xf0/0x268 arp_solicit from neigh_probe+0x54/0x7c neigh_probe from __neigh_event_send+0x22c/0x47c __neigh_event_send from neigh_resolve_output+0x14c/0x1c0 neigh_resolve_output from ip_finish_output2+0x1c8/0x628 ip_finish_output2 from ip_send_skb+0x40/0xd8 ip_send_skb from udp_send_skb+0x124/0x340 udp_send_skb from udp_sendmsg+0x780/0x984 udp_sendmsg from __sys_sendto+0xd8/0x158 __sys_sendto from ret_fast_syscall+0x0/0x58 Let's fix the issue by checking for send_srp() and set_vbus() before calling them. For USB peripheral only cases these both could be NULL.
CVSS 3.1 Base Score 5.5. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
While there are no complete fixes aside from conscientious programming, the following steps will go a long way to ensure that NULL pointer dereferences do not occur.
}
/* make use of pointer1 *//* ... */If you are working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the if statement; and unlock when it has finished.
This example takes an IP address from a user, verifies that it is well formed and then looks up the hostname and copies it into a buffer.
}
strcpy(hostname, hp->h_name);/*routine that ensures user_supplied_addr is in the right format for conversion */If an attacker provides an address that appears to be well-formed, but the address does not resolve to a hostname, then the call to gethostbyaddr() will return NULL. Since the code does not check the return value from gethostbyaddr (CWE-252), a NULL pointer dereference would then occur in the call to strcpy().
Note that this example is also vulnerable to a buffer overflow (see CWE-119).
In the following code, the programmer assumes that the system always has a property named "cmd" defined. If an attacker can control the program's environment so that "cmd" is not defined, the program throws a NULL pointer exception when it attempts to call the trim() method.
cmd = cmd.trim();This application has registered to handle a URL when sent an intent:
}......
}
}int length = URL.length();...The application assumes the URL will always be included in the intent. When the URL is not present, the call to getStringExtra() will return null, thus causing a null pointer exception when length() is called.
ExploitPedia is constantly evolving. Sign up to receive a notification when we release additional functionality.
If you'd like to report a bug or have any suggestions for improvements then please do get in touch with us using this form. We will get back to you as soon as we can.