syzbot

==================================================================
BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274
Write of size 104 at addr ffff888114823210 by task syz.2.17/376

CPU: 0 PID: 376 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <#DB>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 memcpy+0x44/0x70 mm/kasan/shadow.c:66
 __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274
 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline]
 bpf_get_stackid_pe+0x2ee/0x400 kernel/bpf/stackmap.c:334
 bpf_prog_6611c23d801ea08d+0x21/0x36
 bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline]
 __bpf_prog_run include/linux/filter.h:607 [inline]
 bpf_prog_run include/linux/filter.h:614 [inline]
 bpf_overflow_handler+0x3d0/0x5e0 kernel/events/core.c:10238
 __perf_event_overflow+0x437/0x620 kernel/events/core.c:9448
 perf_swevent_overflow kernel/events/core.c:9524 [inline]
 perf_swevent_event+0x2f7/0x530 kernel/events/core.c:-1
 perf_bp_event+0x28c/0x330 kernel/events/core.c:10430
 hw_breakpoint_handler arch/x86/kernel/hw_breakpoint.c:555 [inline]
 hw_breakpoint_exceptions_notify+0x182/0x550 arch/x86/kernel/hw_breakpoint.c:586
 notifier_call_chain kernel/notifier.c:87 [inline]
 atomic_notifier_call_chain kernel/notifier.c:225 [inline]
 notify_die+0x12a/0x1e0 kernel/notifier.c:593
 notify_debug+0x24/0x30 arch/x86/kernel/traps.c:1018
 exc_debug_kernel arch/x86/kernel/traps.c:1075 [inline]
 exc_debug+0xde/0x130 arch/x86/kernel/traps.c:1175
 asm_exc_debug+0x1a/0x40 arch/x86/include/asm/idtentry.h:648
RIP: 0010:__get_user_nocheck_8+0x9/0x13 arch/x86/lib/getuser.S:160
Code: 90 0f 01 cb 0f ae e8 0f b7 10 31 c0 0f 01 ca c3 90 0f 01 cb 0f ae e8 8b 10 31 c0 0f 01 ca c3 90 90 0f 01 cb 0f ae e8 48 8b 10 <31> c0 0f 01 ca c3 90 0f 01 ca 31 d2 48 c7 c0 f2 ff ff ff c3 00 00
RSP: 0000:ffffc90000ab7720 EFLAGS: 00040806
RAX: 0000200000000300 RBX: 0000200000000300 RCX: ffff888113972880
RDX: 00006370692f736e RSI: 0000200000000300 RDI: 00007fffffffeff0
RBP: ffffc90000ab77b0 R08: 000000000000007f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff810a7780 R12: 0000000000000001
R13: 00000000ffffffff R14: 0000000000000000 R15: dffffc0000000000
 </#DB>
 <TASK>
 get_perf_callchain+0x39e/0x490 kernel/events/callchain.c:219
 perf_callchain kernel/events/core.c:7464 [inline]
 perf_prepare_sample+0x399/0x1d40 kernel/events/core.c:7497
 __perf_event_output kernel/events/core.c:7682 [inline]
 perf_event_output_forward+0xd1/0x1a0 kernel/events/core.c:7702
 __perf_event_overflow+0x437/0x620 kernel/events/core.c:9448
 perf_swevent_overflow kernel/events/core.c:9524 [inline]
 perf_swevent_event+0x2f7/0x530 kernel/events/core.c:-1
 perf_bp_event+0x28c/0x330 kernel/events/core.c:10430
 hw_breakpoint_handler arch/x86/kernel/hw_breakpoint.c:555 [inline]
 hw_breakpoint_exceptions_notify+0x278/0x550 arch/x86/kernel/hw_breakpoint.c:586
 notifier_call_chain kernel/notifier.c:87 [inline]
 atomic_notifier_call_chain kernel/notifier.c:225 [inline]
 notify_die+0x12a/0x1e0 kernel/notifier.c:593
 notify_debug+0x24/0x30 arch/x86/kernel/traps.c:1018
 exc_debug_user arch/x86/kernel/traps.c:1144 [inline]
 noist_exc_debug+0x77/0x100 arch/x86/kernel/traps.c:1181
 asm_exc_debug+0x34/0x40 arch/x86/include/asm/idtentry.h:648
RIP: 0033:0x7f5c48d7b43d
Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 89 f8 48 89 fa c5 f9 ef c0 25 ff 0f 00 00 3d e0 0f 00 00 0f 87 27 01 00 00 c5 fd 74 0f <c5> fd d7 c1 85 c0 74 5b f3 0f bc c0 e9 30 01 00 00 66 90 f3 0f bc
RSP: 002b:00007ffc1cecedf8 EFLAGS: 00000283
RAX: 0000000000000300 RBX: 00007ffc1cecf330 RCX: 2f666c65732f636f
RDX: 0000200000000300 RSI: 00007f5c48e5c9c0 RDI: 0000200000000300
RBP: 0000200000000300 R08: 00007ffc1cecf560 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000073 R14: 00007f5c48e31e03 R15: 00007ffc1cecf3f0
 </TASK>

Allocated by task 376:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:380 [inline]
 __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 __do_kmalloc_node mm/slab_common.c:938 [inline]
 __kmalloc_node+0xb2/0x1e0 mm/slab_common.c:945
 kmalloc_node include/linux/slab.h:589 [inline]
 __bpf_map_area_alloc kernel/bpf/syscall.c:328 [inline]
 bpf_map_area_alloc+0x4b/0xe0 kernel/bpf/syscall.c:341
 prealloc_elems_and_freelist+0x8a/0x1e0 kernel/bpf/stackmap.c:51
 stack_map_alloc+0x3a7/0x530 kernel/bpf/stackmap.c:117
 find_and_alloc_map kernel/bpf/syscall.c:133 [inline]
 map_create+0x49c/0xd80 kernel/bpf/syscall.c:1126
 __sys_bpf+0x34e/0x850 kernel/bpf/syscall.c:4987
 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5107
 x64_sys_call+0x488/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888114823200
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 16 bytes inside of
 64-byte region [ffff888114823200, ffff888114823240)

The buggy address belongs to the physical page:
page:ffffea00045208c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x114823
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea0004520500 dead000000000005 ffff888100042780
raw: 0000000000000000 0000000080200020 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 117, tgid 117 (udevadm), ts 4425628532, free_ts 0
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2677
 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583
 __alloc_pages+0x1d9/0x480 mm/page_alloc.c:5897
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1967 [inline]
 new_slab+0x98/0x3d0 mm/slub.c:2020
 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177
 __slab_alloc+0x5e/0xa0 mm/slub.c:3263
 slab_alloc_node mm/slub.c:3348 [inline]
 __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423
 __do_kmalloc_node mm/slab_common.c:937 [inline]
 __kmalloc+0xa1/0x1e0 mm/slab_common.c:951
 kmalloc include/linux/slab.h:568 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 kobject_get_path+0xbf/0x200 lib/kobject.c:152
 kobject_uevent_env+0x2a0/0x730 lib/kobject_uevent.c:544
 kobject_synth_uevent+0x57e/0xbc0 lib/kobject_uevent.c:208
 uevent_store+0x25/0x70 drivers/base/core.c:2690
 dev_attr_store+0x6c/0x90 drivers/base/core.c:2389
 sysfs_kf_write+0x137/0x150 fs/sysfs/file.c:136
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888114823100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888114823180: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888114823200: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff888114823280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888114823300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	0f 01 cb             	stac
   4:	0f ae e8             	lfence
   7:	0f b7 10             	movzwl (%rax),%edx
   a:	31 c0                	xor    %eax,%eax
   c:	0f 01 ca             	clac
   f:	c3                   	ret
  10:	90                   	nop
  11:	0f 01 cb             	stac
  14:	0f ae e8             	lfence
  17:	8b 10                	mov    (%rax),%edx
  19:	31 c0                	xor    %eax,%eax
  1b:	0f 01 ca             	clac
  1e:	c3                   	ret
  1f:	90                   	nop
  20:	90                   	nop
  21:	0f 01 cb             	stac
  24:	0f ae e8             	lfence
  27:	48 8b 10             	mov    (%rax),%rdx
* 2a:	31 c0                	xor    %eax,%eax <-- trapping instruction
  2c:	0f 01 ca             	clac
  2f:	c3                   	ret
  30:	90                   	nop
  31:	0f 01 ca             	clac
  34:	31 d2                	xor    %edx,%edx
  36:	48 c7 c0 f2 ff ff ff 	mov    $0xfffffffffffffff2,%rax
  3d:	c3                   	ret