==================================================================
BUG: KASAN: slab-out-of-bounds in strnchr+0x5e/0x80 lib/string.c:405
Read of size 1 at addr ffff88802ed7a3b0 by task syz.0.18/5990

CPU: 0 UID: 0 PID: 5990 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 strnchr+0x5e/0x80 lib/string.c:405
 bpf_bprintf_prepare+0x167/0x13d0 kernel/bpf/helpers.c:829
 ____bpf_snprintf kernel/bpf/helpers.c:1065 [inline]
 bpf_snprintf+0xd3/0x1b0 kernel/bpf/helpers.c:1049
 bpf_prog_c2925c0a7ac12d80+0x58/0x60
 bpf_dispatcher_nop_func include/linux/bpf.h:1394 [inline]
 __bpf_prog_run include/linux/filter.h:723 [inline]
 bpf_prog_run include/linux/filter.h:730 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run1+0x27f/0x4c0 kernel/trace/bpf_trace.c:2115
 __bpf_trace_rcu_utilization+0xa1/0xf0 include/trace/events/rcu.h:27
 __do_trace_rcu_utilization include/trace/events/rcu.h:27 [inline]
 trace_rcu_utilization+0x191/0x1c0 include/trace/events/rcu.h:27
 rcu_sched_clock_irq+0xd3/0x1280 kernel/rcu/tree.c:2693
 update_process_times+0x23c/0x2f0 kernel/time/timer.c:2474
 tick_sched_handle kernel/time/tick-sched.c:298 [inline]
 tick_nohz_handler+0x3e9/0x710 kernel/time/tick-sched.c:319
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x4d0/0xc30 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217
Code: 5b e9 d3 77 5b 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 c0 7e 92 <65> 8b 15 e8 0d bd 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90003e3f8e0 EFLAGS: 00000246
RAX: ffffffff821471f1 RBX: ffff88813ff23aa8 RCX: ffff888026bb5b80
RDX: 0000000000000000 RSI: 000000013ff25067 RDI: 000000013ff25067
RBP: ffff88813ff24060 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520007c7f0c R12: 1ffff11027fe4755
R13: 000000013ff25067 R14: dffffc0000000000 R15: 000000013ff25067
 __pte_offset_map_lock+0x1b1/0x210 mm/pgtable-generic.c:405
 get_locked_pte include/linux/mm.h:2984 [inline]
 __text_poke+0x2e6/0x9f0 arch/x86/kernel/alternative.c:2525
 text_poke arch/x86/kernel/alternative.c:2610 [inline]
 smp_text_poke_batch_finish+0x394/0x1130 arch/x86/kernel/alternative.c:2918
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240
 static_key_disable+0x1a/0x20 kernel/jump_label.c:248
 tracepoint_remove_func kernel/tracepoint.c:370 [inline]
 tracepoint_probe_unregister+0x80e/0x9b0 kernel/tracepoint.c:504
 bpf_raw_tp_link_release+0x43/0x70 kernel/bpf/syscall.c:3768
 bpf_link_free+0xed/0x330 kernel/bpf/syscall.c:3279
 bpf_link_put_direct kernel/bpf/syscall.c:3322 [inline]
 bpf_link_release+0x6b/0x80 kernel/bpf/syscall.c:3329
 __fput+0x44c/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 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:44 [inline]
 exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
 __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_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ad7b8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc543e12b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000016a87 RCX: 00007f8ad7b8f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 00000004543e15af
R10: 0000001b2f420000 R11: 0000000000000246 R12: 00007f8ad7de5fac
R13: 00007f8ad7de5fa0 R14: ffffffffffffffff R15: 0000000000000003
 </TASK>

Allocated by task 5990:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5657 [inline]
 __kmalloc_node_noprof+0x57a/0x820 mm/slub.c:5663
 kmalloc_node_noprof include/linux/slab.h:987 [inline]
 __bpf_map_area_alloc kernel/bpf/syscall.c:395 [inline]
 bpf_map_area_alloc+0x64/0x180 kernel/bpf/syscall.c:408
 insn_array_alloc+0x52/0x140 kernel/bpf/bpf_insn_array.c:49
 map_create+0xafd/0x16a0 kernel/bpf/syscall.c:1514
 __sys_bpf+0x682/0x8a0 kernel/bpf/syscall.c:6189
 __do_sys_bpf kernel/bpf/syscall.c:6320 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6318 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6318
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802ed7a000
 which belongs to the cache kmalloc-cg-1k of size 1024
The buggy address is located 0 bytes to the right of
 allocated 944-byte region [ffff88802ed7a000, ffff88802ed7a3b0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802ed7f800 pfn:0x2ed78
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880767e8401
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ffb0280 ffffea0000a1de00 0000000000000003
raw: ffff88802ed7f800 0000000080100008 00000000f5000000 ffff8880767e8401
head: 00fff00000000040 ffff88813ffb0280 ffffea0000a1de00 0000000000000003
head: ffff88802ed7f800 0000000080100008 00000000f5000000 ffff8880767e8401
head: 00fff00000000003 ffffea0000bb5e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5726, tgid 5726 (dhcpcd-run-hook), ts 63900695456, free_ts 63848468581
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xf2b/0x1960 mm/slub.c:4656
 __slab_alloc+0x65/0x100 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_noprof+0x47d/0x800 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kmalloc_array_noprof include/linux/slab.h:1003 [inline]
 alloc_pipe_info+0x1fd/0x4d0 fs/pipe.c:817
 get_pipe_inode fs/pipe.c:896 [inline]
 create_pipe_files+0x8a/0x7e0 fs/pipe.c:928
 __do_pipe_flags+0x46/0x1f0 fs/pipe.c:990
 do_pipe2+0x9c/0x170 fs/pipe.c:1038
 __do_sys_pipe2 fs/pipe.c:1056 [inline]
 __se_sys_pipe2 fs/pipe.c:1054 [inline]
 __x64_sys_pipe2+0x5a/0x70 fs/pipe.c:1054
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5731 tgid 5731 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
 discard_slab mm/slub.c:3346 [inline]
 __put_partials+0x146/0x170 mm/slub.c:3886
 put_cpu_partial+0x1f2/0x2d0 mm/slub.c:3961
 __slab_free+0x288/0x2a0 mm/slub.c:5952
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 mt_alloc_one lib/maple_tree.c:174 [inline]
 mas_alloc_nodes+0x291/0x350 lib/maple_tree.c:1110
 mas_preallocate+0x2e0/0x670 lib/maple_tree.c:5194
 vma_iter_prealloc mm/vma.h:502 [inline]
 commit_merge+0x1fd/0x700 mm/vma.c:746
 vma_expand+0x4a3/0xa10 mm/vma.c:1160
 relocate_vma_down+0x2da/0x4f0 mm/vma_exec.c:58
 setup_arg_pages+0x5cf/0xa90 fs/exec.c:690
 load_elf_binary+0xba4/0x2740 fs/binfmt_elf.c:1028
 search_binary_handler fs/exec.c:1669 [inline]
 exec_binprm fs/exec.c:1701 [inline]
 bprm_execve+0x92e/0x1400 fs/exec.c:1753

Memory state around the buggy address:
 ffff88802ed7a280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802ed7a300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88802ed7a380: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
                                     ^
 ffff88802ed7a400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802ed7a480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	5b                   	pop    %rbx
   1:	e9 d3 77 5b 00       	jmp    0x5b77d9
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	f3 0f 1e fa          	endbr64
  1d:	48 8b 04 24          	mov    (%rsp),%rax
  21:	65 48 8b 0c 25 08 c0 	mov    %gs:0xffffffff927ec008,%rcx
  28:	7e 92
* 2a:	65 8b 15 e8 0d bd 10 	mov    %gs:0x10bd0de8(%rip),%edx        # 0x10bd0e19 <-- trapping instruction
  31:	81 e2 00 01 ff 00    	and    $0xff0100,%edx
  37:	74 11                	je     0x4a
  39:	81 fa 00 01 00 00    	cmp    $0x100,%edx
  3f:	75                   	.byte 0x75