{"id":"CVE-2025-21682","title":"In the Linux kernel, the following vulnerability has been resolved:\n\neth: bnxt: always recalculate features after XDP clearing, fix null-deref\n\nRecalculate features when XDP is detached.\n\nBefore:\n  # ip li set dev eth0 xdp obj xdp_dummy.…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\neth: bnxt: always recalculate features after XDP clearing, fix null-deref\n\nRecalculate features when XDP is detached.\n\nBefore:\n  # ip li set dev eth0 xdp obj xdp_dummy.…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.16, < 6.12.11","linux_kernel = 6.13"],"patched":["linux_kernel 6.12.11"],"published":"2025-01-31","updated":"2026-07-14","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21682","references":[{"url":"https://git.kernel.org/stable/c/076a694a42ae3f0466bc6e4126050eeb7b7d299a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/08831a894d18abfaabb5bbde7c2069a7fb41dd93","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/90336fc3d6f5e716ac39a9ddbbde453e23a5aa65","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f0aa6a37a3dbb40b272df5fc6db93c114688adcd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-21682.json"},{"url":"https://access.redhat.com/security/cve/CVE-2025-21682"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2343181"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-21682"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21682"},{"url":"https://lore.kernel.org/linux-cve-announce/2025013103-CVE-2025-21682-ccfd@gregkh/T"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00233,"epssPercentile":0.14488,"ingestedAt":"2026-07-14T13:36:54.943Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2025-10-01T19:51:50.706963Z"},"slug":"CVE-2025-21682","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\neth: bnxt: always recalculate features after XDP clearing, fix null-deref\n\nRecalculate features when XDP is detached.\n\nBefore:\n  # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp\n  # ip li set dev eth0 xdp off\n  # ethtool -k eth0 | grep gro\n  rx-gro-hw: off [requested on]\n\nAfter:\n  # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp\n  # ip li set dev eth0 xdp off\n  # ethtool -k eth0 | grep gro\n  rx-gro-hw: on\n\nThe fact that HW-GRO doesn't get re-enabled automatically is just\na minor annoyance. The real issue is that the features will randomly\ncome back during another reconfiguration which just happens to invoke\nnetdev_update_features(). The driver doesn't handle reconfiguring\ntwo things at a time very robustly.\n\nStarting with commit 98ba1d931f61 (\"bnxt_en: Fix RSS logic in\n__bnxt_reserve_rings()\") we only reconfigure the RSS hash table\nif the \"effective\" number of Rx rings has changed. If HW-GRO is\nenabled \"effective\" number of rings is 2x what user sees.\nSo if we are in the bad state, with HW-GRO re-enablement \"pending\"\nafter XDP off, and we lower the rings by / 2 - the HW-GRO rings\ndoing 2x and the ethtool -L doing / 2 may cancel each other out,\nand the:\n\n  if (old_rx_rings != bp->hw_resc.resv_rx_rings &&\n\ncondition in __bnxt_reserve_rings() will be false.\nThe RSS map won't get updated, and we'll crash with:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000168\n  RIP: 0010:__bnxt_hwrm_vnic_set_rss+0x13a/0x1a0\n    bnxt_hwrm_vnic_rss_cfg_p5+0x47/0x180\n    __bnxt_setup_vnic_p5+0x58/0x110\n    bnxt_init_nic+0xb72/0xf50\n    __bnxt_open_nic+0x40d/0xab0\n    bnxt_open_nic+0x2b/0x60\n    ethtool_set_channels+0x18c/0x1d0\n\nAs we try to access a freed ring.\n\nThe issue is present since XDP support was added, really, but\nprior to commit 98ba1d931f61 (\"bnxt_en: Fix RSS logic in\n__bnxt_reserve_rings()\") it wasn't causing major issues.\n\n## Affected\n\n- `linux_kernel >= 4.16, < 6.12.11`\n- `linux_kernel = 6.13`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.12.11`\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-09-08 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-21682.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}