BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu

Status: upstream: reported C repro on 2026/06/30 06:20
Subsystems: bpf
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+fd7e415d891073b83e1f@syzkaller.appspotmail.com
Fix commit: de020dc8049b bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root]
First crash: 118d, last: now
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
988973dd assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu 2026/06/19 00:08 2026/06/19 00:08 2026/06/19 01:00 24486521
▶ ▼ Discussions (7)
Title Replies (including bot) Last reply
[PATCH bpf v2] bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch() 3 (3) 2026/10/02 11:40
Re: BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu 1 (1) 2026/09/30 07:02
[PATCH bpf] bpf: Fix smp_processor_id() warning in rhtab_delete_elem() 3 (3) 2026/09/29 06:09
[syzbot] Monthly bpf report (Jul 2026) 0 (1) 2026/07/23 04:32
[PATCH v3] bpf: Fix smp_processor_id() call trace for preemptible kernels 9 (9) 2026/07/02 05:40
[syzbot] [bpf?] BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu 3 (7) 2026/06/30 11:22
[PATCH] bpf: Fix smp_processor_id() call trace for preemptible kernels 4 (4) 2026/06/30 09:48
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2026/06/30 09:08 27m eadavis@qq.com patch bpf log
2026/06/30 08:20 27m eadavis@qq.com patch bpf log
2026/06/30 08:17 40m eadavis@qq.com patch bpf log

Sample crash report:
BUG: using smp_processor_id() in preemptible [00000000] code: syz.0.17/5933
caller is bpf_mem_cache_free_rcu+0x41/0xb0 kernel/bpf/memalloc.c:954
CPU: 3 UID: 0 PID: 5933 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 check_preemption_disabled+0xd8/0xe0 lib/smp_processor_id.c:47
 bpf_mem_cache_free_rcu+0x41/0xb0 kernel/bpf/memalloc.c:954
 rhtab_delete_elem+0x96f/0x24e0 kernel/bpf/hashtab.c:2969
 __rhtab_map_lookup_and_delete_batch+0x925/0xf40 kernel/bpf/hashtab.c:3349
 bpf_map_do_batch+0x2b2/0x6d0 kernel/bpf/syscall.c:5830
 __sys_bpf+0xeb8/0x4e80 kernel/bpf/syscall.c:6483
 __do_sys_bpf kernel/bpf/syscall.c:6537 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6534 [inline]
 __x64_sys_bpf+0xce/0x140 kernel/bpf/syscall.c:6534
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f33aab9de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff79abbf18 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f33aae25fa0 RCX: 00007f33aab9de59
RDX: 0000000000000038 RSI: 00002000000018c0 RDI: 0000000000000019
RBP: 00007f33aac33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f33aae25fac R14: 00007f33aae25fa0 R15: 00007f33aae25fa0
 </TASK>

Crashes (2281):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/09 08:12 upstream 0e35b9b6ec0f b9f1ceaa .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/06/18 01:57 bpf e771677c937d b62b3ded .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/06/18 01:28 bpf e771677c937d b62b3ded .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/06/18 01:59 bpf-next 66affa37cfac b62b3ded .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/02 01:42 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 13:55 upstream 551c722f4080 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 12:17 upstream 551c722f4080 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 00:08 upstream 6f8319e3e9a4 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 00:08 upstream 6f8319e3e9a4 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/29 22:56 upstream 6f8319e3e9a4 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/24 07:47 upstream 62f4c998b297 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/23 13:57 upstream fe2ec83746e5 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/21 08:05 upstream 50d05c7c76c9 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/03 08:20 upstream 5e0f8396d480 57bbd979 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/03 08:20 upstream 5e0f8396d480 57bbd979 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 20:49 upstream 551c722f4080 4db88980 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/29 19:43 upstream 6f8319e3e9a4 328436b3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/07 03:25 net ab699d296e06 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/05 17:44 net aaaaf87ea99b 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/02 13:56 bpf 7b12c538697f 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/01 00:05 net 2e7ea988a032 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 07:08 bpf ab39974240a0 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 03:10 bpf ab39974240a0 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 00:41 bpf ab39974240a0 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/09 10:09 net-next 3f65f6ff8594 b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/05 10:22 net-next 8b4e7209c842 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/03 07:09 bpf-next a1739a8ca372 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/03 00:58 bpf-next a1739a8ca372 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/02 12:15 net-next eb0c18404c89 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/02 09:27 net-next eb0c18404c89 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/01 13:17 net-next a0227fa24e8a 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/01 08:34 bpf-next 6a75c73eebd4 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/29 13:40 bpf-next 61c1e63c9b65 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/29 09:33 bpf-next 61c1e63c9b65 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 22:53 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 20:59 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 16:53 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 15:18 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/28 04:47 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/27 22:25 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/27 21:17 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/27 18:16 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/27 08:55 bpf-next ea9358e1270a a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/23 08:33 linux-next a8c591ed6b67 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/14 22:39 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d820e3baa404 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/14 22:30 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d820e3baa404 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/06 22:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe98fb51bf62 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/06 21:27 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe98fb51bf62 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/06 20:08 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe98fb51bf62 f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/05 16:39 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe98fb51bf62 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/10/05 04:16 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe98fb51bf62 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 12:13 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 09:55 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 08:35 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 06:49 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 05:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 04:05 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/30 03:05 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/29 20:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/06 19:38 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 73ae59e97596 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-compat BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/09/06 00:20 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 0f23d56f17fd 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm32 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
2026/08/30 22:40 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 45c13f3f9e3b 2f52988a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64 BUG: using smp_processor_id() in preemptible code in bpf_mem_cache_free_rcu
* Struck through repros no longer work on HEAD.