CVE-2024-27414
May 17, 2024
In the Linux kernel, the following vulnerability has been resolved:
rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back
In the commit d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks
IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic
in the function "rtnl_bridge_setlink" to enable the loop to also check
the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment
removed the "break" statement and led to an error logic of the flags
writing back at the end of this function.
if (have_flags)
memcpy(nla_data(attr), &flags, sizeof(flags));
// attr should point to IFLA_BRIDGE_FLAGS NLA !!!
Before the mentioned commit, the "attr" is granted to be IFLA_BRIDGE_FLAGS.
However, this is not necessarily true fow now as the updated loop will let
the attr point to the last NLA, even an invalid NLA which could cause
overflow writes.
This patch introduces a new variable "br_flag" to save the NLA pointer
that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned
error logic.
Related ResourcesĀ (11)
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Contact UsCVSS v4
Base Score:
5.8
Attack Vector
LOCAL
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.5
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
EPSS
Base Score:
0.04