{"id":"CVE-2026-53094","title":"bpf: Fix stale offload->prog pointer after constant blinding","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix stale offload->prog pointer after constant blinding\n\nWhen a dev-bound-only BPF program (BPF_F_XDP_DEV_BOUND_ONLY) undergoes\nJIT compilation with constant blind…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < a713b72ff88cdab4d5d692908ab1259ada511f4d","Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < 25484c39d1ec82a0368798d956da3de5039b3fe8","Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < 059525cf18e69a9313baf947d8898c6ee7ca6b65","Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < c79f8503d83d4665be461fb9e45e215d0380c67b","Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < a1aa9ef47c299c5bbc30594d3c2f0589edf908e6","Linux 6.3"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:25:39.853859Z"},"published":"2026-06-24","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:31:32.663Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53094","references":[{"url":"https://git.kernel.org/stable/c/a713b72ff88cdab4d5d692908ab1259ada511f4d"},{"url":"https://git.kernel.org/stable/c/25484c39d1ec82a0368798d956da3de5039b3fe8"},{"url":"https://git.kernel.org/stable/c/059525cf18e69a9313baf947d8898c6ee7ca6b65"},{"url":"https://git.kernel.org/stable/c/c79f8503d83d4665be461fb9e45e215d0380c67b"},{"url":"https://git.kernel.org/stable/c/a1aa9ef47c299c5bbc30594d3c2f0589edf908e6"}],"tags":["cve.org"],"epss":0.00129,"epssPercentile":0.02225,"ingestedAt":"2026-10-16T17:24:46.731Z","slug":"CVE-2026-53094","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix stale offload->prog pointer after constant blinding\n\nWhen a dev-bound-only BPF program (BPF_F_XDP_DEV_BOUND_ONLY) undergoes\nJIT compilation with constant blinding enabled (bpf_jit_harden >= 2),\nbpf_jit_blind_constants() clones the program. The original prog is then\nfreed in bpf_jit_prog_release_other(), which updates aux->prog to point\nto the surviving clone, but fails to update offload->prog.\n\nThis leaves offload->prog pointing to the freed original program. When\nthe network namespace is subsequently destroyed, cleanup_net() triggers\nbpf_dev_bound_netdev_unregister(), which iterates ondev->progs and calls\n__bpf_prog_offload_destroy(offload->prog). Accessing the freed prog\ncauses a page fault:\n\nBUG: unable to handle page fault for address: ffffc900085f1038\nWorkqueue: netns cleanup_net\nRIP: 0010:__bpf_prog_offload_destroy+0xc/0x80\nCall Trace:\n__bpf_offload_dev_netdev_unregister+0x257/0x350\nbpf_dev_bound_netdev_unregister+0x4a/0x90\nunregister_netdevice_many_notify+0x2a2/0x660\n...\ncleanup_net+0x21a/0x320\n\nThe test sequence that triggers this reliably is:\n\n1. Set net.core.bpf_jit_harden=2 (echo 2 > /proc/sys/net/core/bpf_jit_harden)\n2. Run xdp_metadata selftest, which creates a dev-bound-only XDP\n   program on a veth inside a netns (./test_progs -t xdp_metadata)\n3. cleanup_net -> page fault in __bpf_prog_offload_destroy\n\nDev-bound-only programs are unique in that they have an offload structure\nbut go through the normal JIT path instead of bpf_prog_offload_compile().\nThis means they are subject to constant blinding's prog clone-and-replace,\nwhile also having offload->prog that must stay in sync.\n\nFix this by updating offload->prog in bpf_jit_prog_release_other(),\nalongside the existing aux->prog update. Both are back-pointers to\nthe prog that must be kept in sync when the prog is replaced.\n\n## Affected\n\n- `Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < a713b72ff88cdab4d5d692908ab1259ada511f4d`\n- `Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < 25484c39d1ec82a0368798d956da3de5039b3fe8`\n- `Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < 059525cf18e69a9313baf947d8898c6ee7ca6b65`\n- `Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < c79f8503d83d4665be461fb9e45e215d0380c67b`\n- `Linux >= 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 < a1aa9ef47c299c5bbc30594d3c2f0589edf908e6`\n- `Linux 6.3`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}