CVE - CVE-2022-48910

CVE-ID
CVE-2022-48910	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: net: ipv6: ensure we call ipv6_mc_down() at most once There are two reasons for addrconf_notify() to be called with NETDEV_DOWN: either the network device is actually going down, or IPv6 was disabled on the interface. If either of them stays down while the other is toggled, we repeatedly call the code for NETDEV_DOWN, including ipv6_mc_down(), while never calling the corresponding ipv6_mc_up() in between. This will cause a new entry in idev->mc_tomb to be allocated for each multicast group the interface is subscribed to, which in turn leaks one struct ifmcaddr6 per nontrivial multicast group the interface is subscribed to. The following reproducer will leak at least $n objects: ip addr add ff2e::4242/32 dev eth0 autojoin sysctl -w net.ipv6.conf.eth0.disable_ipv6=1 for i in $(seq 1 $n); do ip link set up eth0; ip link set down eth0 done Joining groups with IPV6_ADD_MEMBERSHIP (unprivileged) or setting the sysctl net.ipv6.conf.eth0.forwarding to 1 (=> subscribing to ff02::2) can also be used to create a nontrivial idev->mc_list, which will the leak objects with the right up-down-sequence. Based on both sources for NETDEV_DOWN events the interface IPv6 state should be considered: - not ready if the network interface is not ready OR IPv6 is disabled for it - ready if the network interface is ready AND IPv6 is enabled for it The functions ipv6_mc_up() and ipv6_down() should only be run when this state changes. Implement this by remembering when the IPv6 state is ready, and only run ipv6_mc_down() if it actually changed from ready to not ready. The other direction (not ready -> ready) already works correctly, as: - the interface notification triggered codepath for NETDEV_UP / NETDEV_CHANGE returns early if ipv6 is disabled, and - the disable_ipv6=0 triggered codepath skips fully initializing the interface as long as addrconf_link_ready(dev) returns false - calling ipv6_mc_up() repeatedly does not leak anything
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/72124e65a70b84e6303a5cd21b0ac1f27d7d61a4 URL:https://git.kernel.org/stable/c/72124e65a70b84e6303a5cd21b0ac1f27d7d61a4 MISC:https://git.kernel.org/stable/c/9588ac2eddc2f223ebcebf6e9f5caed84d32922b URL:https://git.kernel.org/stable/c/9588ac2eddc2f223ebcebf6e9f5caed84d32922b MISC:https://git.kernel.org/stable/c/9995b408f17ff8c7f11bc725c8aa225ba3a63b1c URL:https://git.kernel.org/stable/c/9995b408f17ff8c7f11bc725c8aa225ba3a63b1c MISC:https://git.kernel.org/stable/c/9a8736b2da28b24f01707f592ff059b9f90a058c URL:https://git.kernel.org/stable/c/9a8736b2da28b24f01707f592ff059b9f90a058c MISC:https://git.kernel.org/stable/c/b11781515208dd31fbcd0b664078dce5dc44523f URL:https://git.kernel.org/stable/c/b11781515208dd31fbcd0b664078dce5dc44523f MISC:https://git.kernel.org/stable/c/c71bf3229f9e9dd60ba02f5a5be02066edf57012 URL:https://git.kernel.org/stable/c/c71bf3229f9e9dd60ba02f5a5be02066edf57012 MISC:https://git.kernel.org/stable/c/f4c63b24dea9cc2043ff845dcca9aaf8109ea38a URL:https://git.kernel.org/stable/c/f4c63b24dea9cc2043ff845dcca9aaf8109ea38a
Assigning CNA
kernel.org
Date Record Created
20240821	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240821)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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