{"id":"CVE-2026-53094","state":"PUBLISHED","title":"bpf: Fix stale offload->prog pointer after constant blinding","description":"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 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.","publishedAt":"2026-06-24T16:30:32.815Z","updatedAt":"2026-10-19T19:57:24.560Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"a713b72ff88cdab4d5d692908ab1259ada511f4d","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"25484c39d1ec82a0368798d956da3de5039b3fe8","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"059525cf18e69a9313baf947d8898c6ee7ca6b65","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"c79f8503d83d4665be461fb9e45e215d0380c67b","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"a1aa9ef47c299c5bbc30594d3c2f0589edf908e6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]}],"references":["https://git.kernel.org/stable/c/a713b72ff88cdab4d5d692908ab1259ada511f4d","https://git.kernel.org/stable/c/25484c39d1ec82a0368798d956da3de5039b3fe8","https://git.kernel.org/stable/c/059525cf18e69a9313baf947d8898c6ee7ca6b65","https://git.kernel.org/stable/c/c79f8503d83d4665be461fb9e45e215d0380c67b","https://git.kernel.org/stable/c/a1aa9ef47c299c5bbc30594d3c2f0589edf908e6"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53094.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53094","state":"PUBLISHED","datePublished":"2026-06-24T16:30:32.815Z","dateUpdated":"2026-10-19T19:57:24.560Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.384Z"},"containers":{"cna":{"title":"bpf: Fix stale offload->prog pointer after constant blinding","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"a713b72ff88cdab4d5d692908ab1259ada511f4d","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"25484c39d1ec82a0368798d956da3de5039b3fe8","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"059525cf18e69a9313baf947d8898c6ee7ca6b65","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"c79f8503d83d4665be461fb9e45e215d0380c67b","versionType":"git"},{"version":"2b3486bc2d237ec345b3942b7be5deabf8c8fed1","status":"affected","lessThan":"a1aa9ef47c299c5bbc30594d3c2f0589edf908e6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]}],"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"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is reached through local `bpf(BPF_PROG_LOAD)` and netlink/netns operations used to create and tear down a device-bound XDP program, not by remote packets.\nAC:L - Once the target has BPF JIT hardening set to blind constants for all users, the trigger is deterministic: load a dev-bound-only XDP program with constants, then unregister the device or destroy the netns. There is no attacker-uncontrolled race to win.\nPR:L - XDP program loading requires BPF and NET_ADMIN privileges, but these can be available in user-namespace/container deployments through BPF token delegation and namespaced capabilities. Under the required rule, this is scored as Low rather than High.\nUI:N - No victim action is required after the attacker has local execution; the attacker can perform the BPF load and netdevice/netns teardown directly.\nS:U - The bug corrupts/dereferences kernel memory within the same kernel security authority. This is standard local kernel compromise/DoS rather than a VM or hardware isolation boundary escape.\nC:H - The stale `offload->prog` is a use-after-free of a `struct bpf_prog`; if reclaimed, the cleanup path trusts attacker-shaped pointers and can be developed into kernel memory disclosure primitives. Kernel UAFs are scored High for confidentiality.\nI:H - The same UAF can drive trusted list/free/write operations through forged `prog->aux` and `offload` pointers, making arbitrary kernel memory corruption or code execution plausible. Kernel UAFs are scored High for integrity.\nA:H - The upstream report shows a reliable kernel page fault during `cleanup_net()`/netdevice unregister when the stale pointer is dereferenced. This is a kernel crash availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:33:20.910Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-53094","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:25:39.853859Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:57:24.560Z"}}]}}}