{"id":"CVE-2023-54303","state":"PUBLISHED","title":"bpf: Disable preemption in bpf_perf_event_output","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Disable preemption in bpf_perf_event_output\n\nThe nesting protection in bpf_perf_event_output relies on disabled\npreemption, which is guaranteed for kprobes and tracepoints.\n\nHowever bpf_perf_event_output can be also called from uprobes context\nthrough bpf_prog_run_array_sleepable function which disables migration,\nbut keeps preemption enabled.\n\nThis can cause task to be preempted by another one inside the nesting\nprotection and lead eventually to two tasks using same perf_sample_data\nbuffer and cause crashes like:\n\n  kernel tried to execute NX-protected page - exploit attempt? (uid: 0)\n  BUG: unable to handle page fault for address: ffffffff82be3eea\n  ...\n  Call Trace:\n   ? __die+0x1f/0x70\n   ? page_fault_oops+0x176/0x4d0\n   ? exc_page_fault+0x132/0x230\n   ? asm_exc_page_fault+0x22/0x30\n   ? perf_output_sample+0x12b/0x910\n   ? perf_event_output+0xd0/0x1d0\n   ? bpf_perf_event_output+0x162/0x1d0\n   ? bpf_prog_c6271286d9a4c938_krava1+0x76/0x87\n   ? __uprobe_perf_func+0x12b/0x540\n   ? uprobe_dispatcher+0x2c4/0x430\n   ? uprobe_notify_resume+0x2da/0xce0\n   ? atomic_notifier_call_chain+0x7b/0x110\n   ? exit_to_user_mode_prepare+0x13e/0x290\n   ? irqentry_exit_to_user_mode+0x5/0x30\n   ? asm_exc_int3+0x35/0x40\n\nFixing this by disabling preemption in bpf_perf_event_output.","publishedAt":"2025-12-30T12:23:37.827Z","updatedAt":"2026-08-05T09:19:03.573Z","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":"8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9","status":"affected","lessThan":"3654ed5daf492463c3faa434c7000d45c2da2ace","versionType":"git"},{"version":"8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9","status":"affected","lessThan":"a0ac32cf61e5a76e2429e486925a52ee41dd75e3","versionType":"git"},{"version":"8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9","status":"affected","lessThan":"f2c67a3e60d1071b65848efaa8c3b66c363dd025","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/bpf_trace.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.45","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.4.10","status":"unaffected","lessThanOrEqual":"6.4.*","versionType":"semver"},{"version":"6.5","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/bpf_trace.c"]}],"references":["https://git.kernel.org/stable/c/3654ed5daf492463c3faa434c7000d45c2da2ace","https://git.kernel.org/stable/c/a0ac32cf61e5a76e2429e486925a52ee41dd75e3","https://git.kernel.org/stable/c/f2c67a3e60d1071b65848efaa8c3b66c363dd025"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:42.242Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/54xxx/CVE-2023-54303.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-54303","state":"PUBLISHED","datePublished":"2025-12-30T12:23:37.827Z","dateUpdated":"2026-08-05T09:19:03.573Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-12-30T12:06:44.529Z"},"containers":{"cna":{"title":"bpf: Disable preemption in bpf_perf_event_output","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Disable preemption in bpf_perf_event_output\n\nThe nesting protection in bpf_perf_event_output relies on disabled\npreemption, which is guaranteed for kprobes and tracepoints.\n\nHowever bpf_perf_event_output can be also called from uprobes context\nthrough bpf_prog_run_array_sleepable function which disables migration,\nbut keeps preemption enabled.\n\nThis can cause task to be preempted by another one inside the nesting\nprotection and lead eventually to two tasks using same perf_sample_data\nbuffer and cause crashes like:\n\n  kernel tried to execute NX-protected page - exploit attempt? (uid: 0)\n  BUG: unable to handle page fault for address: ffffffff82be3eea\n  ...\n  Call Trace:\n   ? __die+0x1f/0x70\n   ? page_fault_oops+0x176/0x4d0\n   ? exc_page_fault+0x132/0x230\n   ? asm_exc_page_fault+0x22/0x30\n   ? perf_output_sample+0x12b/0x910\n   ? perf_event_output+0xd0/0x1d0\n   ? bpf_perf_event_output+0x162/0x1d0\n   ? bpf_prog_c6271286d9a4c938_krava1+0x76/0x87\n   ? __uprobe_perf_func+0x12b/0x540\n   ? uprobe_dispatcher+0x2c4/0x430\n   ? uprobe_notify_resume+0x2da/0xce0\n   ? atomic_notifier_call_chain+0x7b/0x110\n   ? exit_to_user_mode_prepare+0x13e/0x290\n   ? irqentry_exit_to_user_mode+0x5/0x30\n   ? asm_exc_int3+0x35/0x40\n\nFixing this by disabling preemption in bpf_perf_event_output."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9","status":"affected","lessThan":"3654ed5daf492463c3faa434c7000d45c2da2ace","versionType":"git"},{"version":"8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9","status":"affected","lessThan":"a0ac32cf61e5a76e2429e486925a52ee41dd75e3","versionType":"git"},{"version":"8c7dcb84e3b744b2b70baa7a44a9b1881c33a9c9","status":"affected","lessThan":"f2c67a3e60d1071b65848efaa8c3b66c363dd025","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/bpf_trace.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.1.45","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.4.10","status":"unaffected","lessThanOrEqual":"6.4.*","versionType":"semver"},{"version":"6.5","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/bpf_trace.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3654ed5daf492463c3faa434c7000d45c2da2ace"},{"url":"https://git.kernel.org/stable/c/a0ac32cf61e5a76e2429e486925a52ee41dd75e3"},{"url":"https://git.kernel.org/stable/c/f2c67a3e60d1071b65848efaa8c3b66c363dd025"}],"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 code is BPF/uprobe tracing infrastructure reached only by executing code on the machine (hitting an instrumented userspace function via local process execution). There is no remote or adjacent-network entry point.\nAC:L - The attacker controls both racing sides — they run all the threads that hit the uprobe — and can pin them to a single CPU with sched_setaffinity, widen the window with large bpf_perf_event_output payloads, and rely on full preemption being the default on PREEMPT_DYNAMIC distro and Android kernels. Nothing required is outside attacker influence.\nPR:L - In the realistic worst case — a host running a system-wide uprobe/USDT observability agent (bpftrace, BCC, continuous profiler), whose programs use perf_submit()/bpf_perf_event_output by default — any unprivileged local user triggers the corruption merely by executing the instrumented binary concurrently. No capability of the attacker's own is needed.\nUI:N - The attacker's own threads hit the uprobe and generate the preemption; no victim action or interaction is required.\nS:U - The corrupted per-CPU perf_sample_data and the resulting code execution are entirely within the kernel's own security authority, with no crossing into a hypervisor, IOMMU, or other authority.\nC:H - The shared slot leaves data->raw pointing at another task's freed/reused kernel stack, so __output_copy() copies frag->size bytes from an arbitrary frag->data pointer into the mmapped perf ring buffer, yielding arbitrary kernel memory disclosure.\nI:H - __output_custom() performs an indirect call through frag->copy read from a reused kernel stack — confirmed by the \"kernel tried to execute NX-protected page - exploit attempt?\" oops — giving an attacker-sprayable control-flow hijack primitive on top of concurrent writes to a shared perf_sample_data.\nA:H - The commit message documents a reproducible kernel page fault / oops in perf_output_sample, and the race can be re-triggered at will to repeatedly panic the system."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T09:19:03.573Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.4.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.5"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}