CVE-2025-21682 DetailDescriptionIn the Linux kernel, the following vulnerability has been resolved: eth: bnxt: always recalculate features after XDP clearing, fix null-deref Recalculate features when XDP is detached. Before: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: off [requested on] After: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: on The fact that HW-GRO doesn't get re-enabled automatically is just a minor annoyance. The real issue is that the features will randomly come back during another reconfiguration which just happens to invoke netdev_update_features(). The driver doesn't handle reconfiguring two things at a time very robustly. Starting with commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") we only reconfigure the RSS hash table if the "effective" number of Rx rings has changed. If HW-GRO is enabled "effective" number of rings is 2x what user sees. So if we are in the bad state, with HW-GRO re-enablement "pending" after XDP off, and we lower the rings by / 2 - the HW-GRO rings doing 2x and the ethtool -L doing / 2 may cancel each other out, and the: if (old_rx_rings != bp->hw_resc.resv_rx_rings && condition in __bnxt_reserve_rings() will be false. The RSS map won't get updated, and we'll crash with: BUG: kernel NULL pointer dereference, address: 0000000000000168 RIP: 0010:__bnxt_hwrm_vnic_set_rss+0x13a/0x1a0 bnxt_hwrm_vnic_rss_cfg_p5+0x47/0x180 __bnxt_setup_vnic_p5+0x58/0x110 bnxt_init_nic+0xb72/0xf50 __bnxt_open_nic+0x40d/0xab0 bnxt_open_nic+0x2b/0x60 ethtool_set_channels+0x18c/0x1d0 As we try to access a freed ring. The issue is present since XDP support was added, really, but prior to commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") it wasn't causing major issues. Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
CVSS 3.x Severity and Vector Strings:
References to Advisories, Solutions, and ToolsBy selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to nvd@nist.gov.
Weakness Enumeration
Known Affected Software Configurations Switch to CPE 2.2 Configuration 1 ( hide )
Denotes Vulnerable Software Quick InfoCVE Dictionary Entry:CVE-2025-21682 NVD Published Date: 01/31/2025 NVD Last Modified: 02/04/2025 Source: kernel.org |