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
First crash: 61d, last: 5h42m
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 (4)
Title Replies (including bot) Last reply
[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 (1721):
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
2026/08/14 00:59 upstream 3aa1dcaa4f6f a9ede23c .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
2026/08/14 00:27 upstream 3aa1dcaa4f6f a9ede23c .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
2026/08/07 12:00 upstream f9a2394a2348 e4ef95d6 .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
2026/08/07 08:46 upstream f9a2394a2348 c38879ea .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
2026/08/06 20:17 upstream 0d8395707651 c38879ea .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
2026/08/06 19:37 upstream 0d8395707651 c38879ea .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
2026/08/06 03:29 upstream 0d8395707651 cd5b1963 .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
2026/06/25 19:21 upstream ab9de95c9cf9 432fd51a .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
2026/06/20 13:49 upstream 1a3746ccbb0a 43bfcdb0 .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
2026/08/04 21:34 upstream 562bfb501c54 3c5eaa21 .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
2026/06/20 13:56 upstream 1a3746ccbb0a 43bfcdb0 .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
2026/08/16 22:32 bpf a13307e97d5c 746171ee .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
2026/08/16 03:11 bpf a13307e97d5c 746171ee .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
2026/08/15 21:58 bpf a13307e97d5c 746171ee .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
2026/08/15 19:28 bpf a13307e97d5c 746171ee .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
2026/08/15 08:34 bpf a13307e97d5c 746171ee .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
2026/08/14 19:34 net 24ef02f934ee 746171ee .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
2026/08/11 18:16 net b37971686ec5 37a258dd .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
2026/08/10 15:39 net dd057113ac7b 039457bd .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
2026/08/10 06:04 bpf a13307e97d5c 5d63f80b .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
2026/08/09 10:56 bpf a13307e97d5c 5d63f80b .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
2026/08/09 05:01 bpf a13307e97d5c 5d63f80b .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
2026/08/09 03:01 bpf a13307e97d5c 5d63f80b .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
2026/08/09 01:13 bpf a13307e97d5c 5d63f80b .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
2026/08/08 19:00 net dd057113ac7b 5d63f80b .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
2026/08/08 05:45 net 3dbb44d88b1e e4ef95d6 .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
2026/08/07 18:39 bpf 7a3c0289c3c8 e4ef95d6 .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
2026/08/07 06:56 net 594d90519502 c38879ea .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
2026/08/18 08:32 bpf-next f79066c78402 1e72964b .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
2026/08/18 08:32 bpf-next f79066c78402 1e72964b .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
2026/08/18 03:44 net-next 2bd4177d964d 1e72964b .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
2026/08/17 12:07 bpf-next 8eb189206464 746171ee .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
2026/08/17 06:15 bpf-next c93cbdb13f99 746171ee .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
2026/08/16 20:01 bpf-next c93cbdb13f99 746171ee .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
2026/08/15 15:35 bpf-next d82ebfc685c9 746171ee .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
2026/08/15 06:04 bpf-next 409a9bda0429 746171ee .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
2026/08/15 04:26 bpf-next 409a9bda0429 746171ee .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
2026/08/14 12:19 bpf-next 4d9551b39aeb b13552fe .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
2026/08/12 20:36 bpf-next 07cb86aa5081 7ae4acc7 .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
2026/08/12 19:30 bpf-next 07cb86aa5081 7ae4acc7 .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
2026/08/12 06:30 bpf-next 07cb86aa5081 f8d35649 .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
2026/08/12 01:28 bpf-next 07cb86aa5081 f8d35649 .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
2026/08/11 08:14 bpf-next d114bb989367 039457bd .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
2026/08/11 03:58 bpf-next d114bb989367 039457bd .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
2026/08/10 20:05 bpf-next d114bb989367 039457bd .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
2026/08/10 01:21 bpf-next d114bb989367 5d63f80b .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
2026/08/09 18:00 bpf-next d114bb989367 5d63f80b .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
2026/08/09 08:13 bpf-next d114bb989367 5d63f80b .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
2026/08/09 05:29 bpf-next d114bb989367 5d63f80b .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
2026/08/08 02:08 bpf-next 41c129fdc28b e4ef95d6 .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
2026/08/07 16:09 net-next 4fa4977a0d90 e4ef95d6 .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
2026/08/07 03:23 bpf-next 7d008cde75c0 c38879ea .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
2026/08/07 01:04 linux-next 1701fda2f58e c38879ea .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
2026/08/05 20:54 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 7235a3e71949 cd5b1963 .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
2026/07/16 04:20 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 58717b2a1365 27a8bd60 .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
2026/06/19 06:47 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 83f1454877cc d7ffd47b .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.