CVE-2026-64545
net, bpf: check master for NULL in xdp_master_redirect()
Description
In the Linux kernel, the following vulnerability has been resolved: net, bpf: check master for NULL in xdp_master_redirect() xdp_master_redirect() dereferences the result of netdev_master_upper_dev_get_rcu() without a NULL check, but that helper returns NULL when the receiving device has no upper-master adjacency. The reach guard only checks netif_is_bond_slave(). On bond slave release bond_upper_dev_unlink() drops the upper-master adjacency before clearing IFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window still passes netif_is_bond_slave() while master is already NULL, and faults on master->flags at offset 0xb0: BUG: kernel NULL pointer dereference, address: 00000000000000b0 RIP: 0010:xdp_master_redirect (net/core/filter.c:4432) Call Trace: xdp_master_redirect (net/core/filter.c:4432) bpf_prog_run_generic_xdp (include/net/xdp.h:700) do_xdp_generic (net/core/dev.c:5608) __netif_receive_skb_one_core (net/core/dev.c:6204) process_backlog (net/core/dev.c:6319) __napi_poll (net/core/dev.c:7729) net_rx_action (net/core/dev.c:7792) handle_softirqs (kernel/softirq.c:622) __dev_queue_xmit (include/linux/bottom_half.h:33) packet_sendmsg (net/packet/af_packet.c:3082) __sys_sendto (net/socket.c:2252) Kernel panic - not syncing: Fatal exception in interrupt The missing check dates back to the original code; commit 1921f91298d1 ("net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master") later added the master->flags read where the fault now lands but kept the unconditional deref. Check master for NULL before use; a NULL master is treated the same as one that is not up.
INFO
Published Date :
July 27, 2026, 9:17 p.m.
Last Modified :
July 27, 2026, 9:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-64545
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel.
- Ensure NULL checks protect device references.
- Rebuild and deploy the patched kernel.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64545.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64545 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64545
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64545 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64545 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 27, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '879af96ffd72706c6e3278ea6b45b0b0e37ec5d7', 'lessThan': 'c99ca049e910d61ddbd28cc2c47242f2bfbb4970', 'versionType': 'git'}, {'status': 'affected', 'version': '879af96ffd72706c6e3278ea6b45b0b0e37ec5d7', 'lessThan': 'e2a56441233131fe18a76001de347ecda217e40c', 'versionType': 'git'}, {'status': 'affected', 'version': '879af96ffd72706c6e3278ea6b45b0b0e37ec5d7', 'lessThan': '3876318ea54e83eb70982b8280a3c5e4e32269bf', 'versionType': 'git'}, {'status': 'affected', 'version': '879af96ffd72706c6e3278ea6b45b0b0e37ec5d7', 'lessThan': '4edbcacca09f92b85d3951b6add11894b20a84bc', 'versionType': 'git'}, {'status': 'affected', 'version': '879af96ffd72706c6e3278ea6b45b0b0e37ec5d7', 'lessThan': '03b743586a2469744e96e9c1015096d07240935d', 'versionType': 'git'}, {'status': 'affected', 'version': '879af96ffd72706c6e3278ea6b45b0b0e37ec5d7', 'lessThan': '89c103d702b25ceb2d097faf854deb47b53b17ff', 'versionType': 'git'}, {'status': 'affected', 'version': '879af96ffd72706c6e3278ea6b45b0b0e37ec5d7', 'lessThan': 'e82d8cc4321c373dc46e741cd2dfdaa7921fddb7', 'versionType': 'git'}], 'programFiles': ['net/core/filter.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/core/filter.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: net, bpf: check master for NULL in xdp_master_redirect() xdp_master_redirect() dereferences the result of netdev_master_upper_dev_get_rcu() without a NULL check, but that helper returns NULL when the receiving device has no upper-master adjacency. The reach guard only checks netif_is_bond_slave(). On bond slave release bond_upper_dev_unlink() drops the upper-master adjacency before clearing IFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window still passes netif_is_bond_slave() while master is already NULL, and faults on master->flags at offset 0xb0: BUG: kernel NULL pointer dereference, address: 00000000000000b0 RIP: 0010:xdp_master_redirect (net/core/filter.c:4432) Call Trace: xdp_master_redirect (net/core/filter.c:4432) bpf_prog_run_generic_xdp (include/net/xdp.h:700) do_xdp_generic (net/core/dev.c:5608) __netif_receive_skb_one_core (net/core/dev.c:6204) process_backlog (net/core/dev.c:6319) __napi_poll (net/core/dev.c:7729) net_rx_action (net/core/dev.c:7792) handle_softirqs (kernel/softirq.c:622) __dev_queue_xmit (include/linux/bottom_half.h:33) packet_sendmsg (net/packet/af_packet.c:3082) __sys_sendto (net/socket.c:2252) Kernel panic - not syncing: Fatal exception in interrupt The missing check dates back to the original code; commit 1921f91298d1 ("net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master") later added the master->flags read where the fault now lands but kept the unconditional deref. Check master for NULL before use; a NULL master is treated the same as one that is not up. Added Reference https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d Added Reference https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf Added Reference https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc Added Reference https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff Added Reference https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970 Added Reference https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c Added Reference https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7