In the Linux kernel, the following vulnerability has been resolved:
bpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded
bond_option_mode_set() already rejects mode changes that would make a
loaded XDP program incompatible via bond_xdp_check(). However,
bond_option_xmit_hash_policy_set() has no such guard.
For 802.3ad and balance-xor modes, bond_xdp_check() returns false when
xmit_hash_policy is vlan+srcmac, because the 802.1q payload is usually
absent due to hardware offload. This means a user can:
1. Attach a native XDP program to a bond in 802.3ad/balance-xor mode
with a compatible xmit_hash_policy (e.g. layer2+3).
2. Change xmit_hash_policy to vlan+srcmac while XDP remains loaded.
This leaves bond->xdp_prog set but bond_xdp_check() now returning false
for the same device. When the bond is later destroyed, dev_xdp_uninstall()
calls bond_xdp_set(dev, NULL, NULL) to remove the program, which hits
the bond_xdp_check() guard and returns -EOPNOTSUPP, triggering:
WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL))
Fix this by rejecting xmit_hash_policy changes to vlan+srcmac when an
XDP program is loaded on a bond in 802.3ad or balance-xor mode.
commit 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP")
introduced bond_xdp_check() which returns false for 802.3ad/balance-xor
modes when xmit_hash_policy is vlan+srcmac. The check was wired into
bond_xdp_set() to reject XDP attachment with an incompatible policy, but
the symmetric path -- preventing xmit_hash_policy from being changed to an
incompatible value after XDP is already loaded -- was left unguarded in
bond_option_xmit_hash_policy_set().
Note:
commit 094ee6017ea0 ("bonding: check xdp prog when set bond mode")
later added a similar guard to bond_option_mode_set(), but
bond_option_xmit_hash_policy_set() remained unprotected.
bpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded
bond_option_mode_set() already rejects mode changes that would make a
loaded XDP program incompatible via bond_xdp_check(). However,
bond_option_xmit_hash_policy_set() has no such guard.
For 802.3ad and balance-xor modes, bond_xdp_check() returns false when
xmit_hash_policy is vlan+srcmac, because the 802.1q payload is usually
absent due to hardware offload. This means a user can:
1. Attach a native XDP program to a bond in 802.3ad/balance-xor mode
with a compatible xmit_hash_policy (e.g. layer2+3).
2. Change xmit_hash_policy to vlan+srcmac while XDP remains loaded.
This leaves bond->xdp_prog set but bond_xdp_check() now returning false
for the same device. When the bond is later destroyed, dev_xdp_uninstall()
calls bond_xdp_set(dev, NULL, NULL) to remove the program, which hits
the bond_xdp_check() guard and returns -EOPNOTSUPP, triggering:
WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL))
Fix this by rejecting xmit_hash_policy changes to vlan+srcmac when an
XDP program is loaded on a bond in 802.3ad or balance-xor mode.
commit 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP")
introduced bond_xdp_check() which returns false for 802.3ad/balance-xor
modes when xmit_hash_policy is vlan+srcmac. The check was wired into
bond_xdp_set() to reject XDP attachment with an incompatible policy, but
the symmetric path -- preventing xmit_hash_policy from being changed to an
incompatible value after XDP is already loaded -- was left unguarded in
bond_option_xmit_hash_policy_set().
Note:
commit 094ee6017ea0 ("bonding: check xdp prog when set bond mode")
later added a similar guard to bond_option_mode_set(), but
bond_option_xmit_hash_policy_set() remained unprotected.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 25 Mar 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: bpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded bond_option_mode_set() already rejects mode changes that would make a loaded XDP program incompatible via bond_xdp_check(). However, bond_option_xmit_hash_policy_set() has no such guard. For 802.3ad and balance-xor modes, bond_xdp_check() returns false when xmit_hash_policy is vlan+srcmac, because the 802.1q payload is usually absent due to hardware offload. This means a user can: 1. Attach a native XDP program to a bond in 802.3ad/balance-xor mode with a compatible xmit_hash_policy (e.g. layer2+3). 2. Change xmit_hash_policy to vlan+srcmac while XDP remains loaded. This leaves bond->xdp_prog set but bond_xdp_check() now returning false for the same device. When the bond is later destroyed, dev_xdp_uninstall() calls bond_xdp_set(dev, NULL, NULL) to remove the program, which hits the bond_xdp_check() guard and returns -EOPNOTSUPP, triggering: WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL)) Fix this by rejecting xmit_hash_policy changes to vlan+srcmac when an XDP program is loaded on a bond in 802.3ad or balance-xor mode. commit 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP") introduced bond_xdp_check() which returns false for 802.3ad/balance-xor modes when xmit_hash_policy is vlan+srcmac. The check was wired into bond_xdp_set() to reject XDP attachment with an incompatible policy, but the symmetric path -- preventing xmit_hash_policy from being changed to an incompatible value after XDP is already loaded -- was left unguarded in bond_option_xmit_hash_policy_set(). Note: commit 094ee6017ea0 ("bonding: check xdp prog when set bond mode") later added a similar guard to bond_option_mode_set(), but bond_option_xmit_hash_policy_set() remained unprotected. | |
| Title | bpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-03-25T10:27:05.943Z
Reserved: 2026-01-13T15:37:45.994Z
Link: CVE-2026-23310
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-03-25T11:16:27.160
Modified: 2026-03-25T11:16:27.160
Link: CVE-2026-23310
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.