syzbot


KASAN: slab-use-after-free Read in bpf_trace_run2 (3)

Status: upstream: reported syz repro on 2026/02/21 04:46
Subsystems: trace bpf
[Documentation on labels]
Reported-by: syzbot+59701a78e84b0bccfe1b@syzkaller.appspotmail.com
First crash: 20d, last: 7h18m
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly trace report (Feb 2026) 0 (1) 2026/02/23 08:39
[syzbot] [trace?] [bpf?] KASAN: slab-use-after-free Read in bpf_trace_run2 (3) 0 (7) 2026/02/21 23:34
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in bpf_trace_run2 bpf trace 19 C error 653 697d 715d 25/29 fixed on 2024/05/22 23:16
upstream KASAN: slab-use-after-free Read in bpf_trace_run2 (2) bpf trace 19 syz error 123 487d 504d 28/29 fixed on 2025/05/06 15:33
android-54 BUG: unable to handle kernel paging request in bpf_trace_run2 8 C 4 1836d 1991d 0/2 auto-obsoleted due to no activity on 2023/04/17 21:30
upstream KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2 trace bpf 17 C done done 5 1834d 1992d 20/29 fixed on 2021/04/13 19:14
Last patch testing requests (6)
Created Duration User Patch Repo Result
2026/02/21 23:34 15m kartikey406@gmail.com patch upstream log
2026/02/21 12:07 16m kartikey406@gmail.com patch upstream log
2026/02/21 10:45 15m kartikey406@gmail.com patch upstream log
2026/02/21 06:41 15m kartikey406@gmail.com patch upstream log
2026/02/21 05:41 15m kartikey406@gmail.com patch upstream log
2026/02/21 05:19 16m kartikey406@gmail.com patch upstream log

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in __bpf_trace_run kernel/trace/bpf_trace.c:2085 [inline]
BUG: KASAN: slab-use-after-free in bpf_trace_run2+0x2c4/0x840 kernel/trace/bpf_trace.c:2129
Read of size 8 at addr ffff888059440880 by task kworker/u4:2/30

CPU: 0 UID: 0 PID: 30 Comm: kworker/u4:2 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
Workqueue: bat_events batadv_mcast_mla_update
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 __bpf_trace_run kernel/trace/bpf_trace.c:2085 [inline]
 bpf_trace_run2+0x2c4/0x840 kernel/trace/bpf_trace.c:2129
 __do_trace_kfree include/trace/events/kmem.h:97 [inline]
 trace_kfree include/trace/events/kmem.h:97 [inline]
 kfree+0x5b2/0x630 mm/slub.c:6447
 batadv_mcast_mla_list_free net/batman-adv/multicast.c:667 [inline]
 __batadv_mcast_mla_update net/batman-adv/multicast.c:924 [inline]
 batadv_mcast_mla_update+0x3380/0x3740 net/batman-adv/multicast.c:946
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 7677:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5358
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 bpf_raw_tp_link_attach+0x278/0x700 kernel/bpf/syscall.c:4264
 bpf_raw_tracepoint_open+0x1b2/0x220 kernel/bpf/syscall.c:4312
 __sys_bpf+0x846/0x950 kernel/bpf/syscall.c:6270
 __do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1049:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2692 [inline]
 slab_free mm/slub.c:6143 [inline]
 kfree+0x1c1/0x630 mm/slub.c:6461
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 __alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
 nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 __call_rcu_common kernel/rcu/tree.c:3131 [inline]
 call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
 bpf_link_put_direct kernel/bpf/syscall.c:3323 [inline]
 bpf_link_release+0x6b/0x80 kernel/bpf/syscall.c:3330
 __fput+0x44f/0xa70 fs/file_table.c:469
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888059440800
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
 freed 192-byte region [ffff888059440800, ffff8880594408c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x59440
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801ac413c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x1d2cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6361, tgid 6360 (syz.5.357), ts 150596059693, free_ts 150584593785
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3269 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3458
 new_slab mm/slub.c:3516 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7153
 refill_sheaf mm/slub.c:2818 [inline]
 __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4592
 alloc_from_pcs mm/slub.c:4695 [inline]
 slab_alloc_node mm/slub.c:4829 [inline]
 __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5353
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 bpf_raw_tp_link_attach+0x278/0x700 kernel/bpf/syscall.c:4264
 bpf_raw_tracepoint_open+0x1b2/0x220 kernel/bpf/syscall.c:4312
 __sys_bpf+0x846/0x950 kernel/bpf/syscall.c:6270
 __do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 15 tgid 15 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
 __tlb_remove_table_free mm/mmu_gather.c:228 [inline]
 tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:291
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1063
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888059440780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888059440800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888059440880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff888059440900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888059440980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (37):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/04 16:16 upstream 0031c06807cf e6b6b96b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/20 11:34 upstream 8bf22c33e7a1 17d780d6 .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/03/06 17:16 upstream 5ee8dbf54602 41d8037d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/03/04 13:58 upstream 0031c06807cf e6b6b96b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/03/03 02:44 upstream af4e9ef3d784 28b83e23 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/03/01 20:05 upstream eb71ab2bf722 43249bac .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/03/01 09:48 upstream eb71ab2bf722 43249bac .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/28 11:18 upstream 4d349ee5c778 43249bac .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/28 01:48 upstream a75cb869a8cc 2cf092b8 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/27 00:20 upstream 3f4a08e64442 a2f13f71 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/27 00:14 upstream 3f4a08e64442 a2f13f71 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/26 23:47 upstream 3f4a08e64442 a2f13f71 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/26 01:49 upstream d9d32e5bd5a4 e0f78d93 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/25 19:10 upstream 7dff99b35460 c162cde9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/25 13:23 upstream 7dff99b35460 c162cde9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/25 05:45 upstream 7dff99b35460 787dfb7c .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/24 10:54 upstream 7dff99b35460 96b1aa46 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/22 21:17 upstream 189f164e573e 6e7b5511 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/22 11:27 upstream 32a92f8c8932 6e7b5511 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/22 10:09 upstream 32a92f8c8932 6e7b5511 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/20 18:22 upstream 8bf22c33e7a1 741f5161 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/20 10:17 upstream 8bf22c33e7a1 17d780d6 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/19 12:17 upstream 956b9cbd7f15 746545b8 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/18 14:03 upstream 2961f841b025 39751c21 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/16 13:40 upstream 0f2acd3148e0 1e62d198 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/15 07:44 upstream 3e48a11675c5 1e62d198 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/14 16:27 upstream 770aaedb461a 1e62d198 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/02/14 14:04 upstream 770aaedb461a 1e62d198 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in bpf_trace_run2
2026/03/06 01:24 upstream 5ee8dbf54602 31e9c887 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/03/03 15:32 upstream af4e9ef3d784 4180d919 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/03/02 06:57 upstream 39c633261414 43249bac .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/02/25 19:03 upstream 7dff99b35460 c162cde9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/02/23 15:38 upstream 6de23f81a5e0 7c9658af .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/02/18 19:36 upstream 2961f841b025 77d4d919 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/02/17 23:13 upstream d295082ea672 f4288eed .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/02/16 00:52 upstream 26a4cfaff82a 1e62d198 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
2026/02/15 16:01 upstream ca4ee40bf13d 1e62d198 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Read in bpf_trace_run2
* Struck through repros no longer work on HEAD.