[syzbot] [bpf?] [trace?] KASAN: slab-use-after-free Read in bpf_trace_run3 (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 32a92f8c8932 Convert more 'alloc_obj' cases to default GFP..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10f64152580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2208a171312e89b7
dashboard link: https://syzkaller.appspot.com/bug?extid=9ea7c90be2b24e189592
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16eaa55a580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-32a92f8c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/78386dbc59f1/vmlinux-32a92f8c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b38bbd9a7831/bzImage-32a92f8c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9ea7c9...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
BUG: KASAN: slab-use-after-free in bpf_trace_run3+0xdd/0x850 kernel/trace/bpf_trace.c:2130
Read of size 8 at addr ffff888054ecb718 by task syz-executor/5447

CPU: 0 UID: 0 PID: 5447 Comm: syz-executor 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_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:2075 [inline]
bpf_trace_run3+0xdd/0x850 kernel/trace/bpf_trace.c:2130
__bpf_trace_mmap_lock_acquire_returned+0x17e/0x1d0 include/trace/events/mmap_lock.h:47
__traceiter_mmap_lock_acquire_returned+0x87/0xe0 include/trace/events/mmap_lock.h:47
__do_trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline]
trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline]
__mmap_lock_do_trace_acquire_returned+0x1a1/0x210 mm/mmap_lock.c:35
__mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:42 [inline]
mmap_write_lock_killable include/linux/mmap_lock.h:557 [inline]
dup_mmap+0x23d/0x1d90 mm/mmap.c:1740
dup_mm kernel/fork.c:1530 [inline]
copy_mm+0x13b/0x4b0 kernel/fork.c:1582
copy_process+0x18b6/0x3cf0 kernel/fork.c:2223
kernel_clone+0x248/0x8e0 kernel/fork.c:2654
__do_sys_clone kernel/fork.c:2795 [inline]
__se_sys_clone kernel/fork.c:2779 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2779
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
RIP: 0033:0x7f392a1c50d2
Code: 89 e7 e8 b1 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007fffdffb7f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fffdffb7f00 RCX: 00007f392a1c50d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fffdffb808c R08: 0000000000000000 R09: 0000000000000000
R10: 0000555578a147d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 000000000002f577 R15: 00007fffdffb80e0
</TASK>

Allocated by task 5916:
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:5339
kmalloc_noprof include/linux/slab.h:962 [inline]
kzalloc_noprof include/linux/slab.h:1200 [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 5447:
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:2687 [inline]
slab_free mm/slub.c:6124 [inline]
kfree+0x1c1/0x630 mm/slub.c:6442
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 kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

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 ffff888054ecb700
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 24 bytes inside of
freed 192-byte region [ffff888054ecb700, ffff888054ecb7c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888054ecbd00 pfn:0x54ecb
flags: 0x4fff00000000200(workingset|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000200 ffff88801a8413c0 ffffea0001629850 ffff888030400288
raw: ffff888054ecbd00 000000000010000d 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 5909, tgid 5909 (syz.4.241), ts 194010998968, free_ts 194010573612
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:3255 [inline]
allocate_slab+0x77/0x660 mm/slub.c:3444
new_slab mm/slub.c:3502 [inline]
refill_objects+0x331/0x3c0 mm/slub.c:7134
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4578
alloc_from_pcs mm/slub.c:4681 [inline]
slab_alloc_node mm/slub.c:4815 [inline]
__kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5334
kmalloc_noprof include/linux/slab.h:962 [inline]
kzalloc_noprof include/linux/slab.h:1200 [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 5913 tgid 5913 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
vfree+0x25a/0x400 mm/vmalloc.c:3479
bpf_prog_calc_tag+0x315/0x370 kernel/bpf/core.c:335
resolve_pseudo_ldimm64+0xbd/0xc90 kernel/bpf/verifier.c:21701
bpf_check+0x1d83/0x1ce00 kernel/bpf/verifier.c:25958
bpf_prog_load+0x1484/0x1ae0 kernel/bpf/syscall.c:3089
__sys_bpf+0x618/0x950 kernel/bpf/syscall.c:6228
__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

Memory state around the buggy address:
ffff888054ecb600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888054ecb680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888054ecb700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888054ecb780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888054ecb800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[Qing Wang]

#syz test

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2d14fb6d0ed0..038bf4436959 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3783,6 +3783,8 @@ static void bpf_raw_tp_link_release(struct bpf_link *link)

bpf_probe_unregister(raw_tp->btp, raw_tp);
bpf_put_raw_tracepoint(raw_tp->btp);
+
+ synchronize_rcu();
}

static void bpf_raw_tp_link_dealloc(struct bpf_link *link)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in bpf_trace_run3

==================================================================
BUG: KASAN: slab-use-after-free in __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
BUG: KASAN: slab-use-after-free in bpf_trace_run3+0xdd/0x850 kernel/trace/bpf_trace.c:2130

Read of size 8 at addr ffff888047c32a18 by task syz.0.2435/10835

CPU: 0 UID: 0 PID: 10835 Comm: syz.0.2435 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_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:2075 [inline]
bpf_trace_run3+0xdd/0x850 kernel/trace/bpf_trace.c:2130
__bpf_trace_mmap_lock_acquire_returned+0x17e/0x1d0 include/trace/events/mmap_lock.h:47

__do_trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline]
trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline]
__mmap_lock_do_trace_acquire_returned+0x1a1/0x210 mm/mmap_lock.c:35
__mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:42 [inline]
mmap_write_lock_killable include/linux/mmap_lock.h:557 [inline]

do_mprotect_pkey+0x389/0xcd0 mm/mprotect.c:832
__do_sys_mprotect mm/mprotect.c:951 [inline]
__se_sys_mprotect mm/mprotect.c:948 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:948

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

RIP: 0033:0x7fa0dcb9c427
Code: 89 38 eb 84 0f 1f 80 00 00 00 00 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff e9 7a ff ff ff b8 0a 00 00 00 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:00007fff44e34e58 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007fa0ddad26c0 RCX: 00007fa0dcb9c427
RDX: 0000000000000003 RSI: 0000000000020000 RDI: 00007fa0ddab3000
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000021000 R11: 0000000000000206 R12: 00007fff44e34fb0
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
</TASK>

Allocated by task 10832:

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:5339
kmalloc_noprof include/linux/slab.h:962 [inline]
kzalloc_noprof include/linux/slab.h:1200 [inline]

bpf_raw_tp_link_attach+0x278/0x700 kernel/bpf/syscall.c:4266
bpf_raw_tracepoint_open+0x1b2/0x220 kernel/bpf/syscall.c:4314
__sys_bpf+0x846/0x950 kernel/bpf/syscall.c:6272
__do_sys_bpf kernel/bpf/syscall.c:6343 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6341 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6341

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 5963:

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:2687 [inline]
slab_free mm/slub.c:6124 [inline]
kfree+0x1c1/0x630 mm/slub.c:6442
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]
update_defense_level+0x91e/0xd70 net/netfilter/ipvs/ip_vs_ctl.c:209
defense_work_handler+0x2d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:234
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 ffff888047c32a00

which belongs to the cache kmalloc-192 of size 192
The buggy address is located 24 bytes inside of

freed 192-byte region [ffff888047c32a00, ffff888047c32ac0)

The buggy address belongs to the physical page:

page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x47c32
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801ac413c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5734, tgid 5734 (syz-executor), ts 170582106129, free_ts 164219023362

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:3255 [inline]
allocate_slab+0x77/0x660 mm/slub.c:3444
new_slab mm/slub.c:3502 [inline]
refill_objects+0x331/0x3c0 mm/slub.c:7134
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4578
alloc_from_pcs mm/slub.c:4681 [inline]
slab_alloc_node mm/slub.c:4815 [inline]
__kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5334
kmalloc_noprof include/linux/slab.h:962 [inline]
kzalloc_noprof include/linux/slab.h:1200 [inline]

kset_create lib/kobject.c:965 [inline]
kset_create_and_add+0x5a/0x170 lib/kobject.c:1008
register_queue_kobjects net/core/net-sysfs.c:2106 [inline]
netdev_register_kobject+0x1a2/0x310 net/core/net-sysfs.c:2362
register_netdevice+0x12c0/0x1cf0 net/core/dev.c:11422
nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1063 [inline]
nsim_create+0xb92/0x1100 drivers/net/netdevsim/netdev.c:1145
__nsim_dev_port_add+0x72a/0xb50 drivers/net/netdevsim/dev.c:1493
nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1549
nsim_drv_probe+0x905/0xc20 drivers/net/netdevsim/dev.c:1710
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:661
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
page last free pid 29 tgid 29 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

__folio_put+0x414/0x4f0 mm/swap.c:112
folio_put include/linux/mm.h:1817 [inline]
migrate_folio_done mm/migrate.c:1199 [inline]
migrate_folio_move mm/migrate.c:1413 [inline]
migrate_folios_move mm/migrate.c:1721 [inline]
migrate_pages_batch+0x3593/0x4d80 mm/migrate.c:1977
migrate_pages_sync mm/migrate.c:2007 [inline]
migrate_pages+0x1c74/0x2a70 mm/migrate.c:2116
compact_zone+0x26cd/0x4850 mm/compaction.c:2647
compact_node+0x21a/0x320 mm/compaction.c:2916
kcompactd+0xc20/0x1330 mm/compaction.c:3214
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:

ffff888047c32900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888047c32980: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
>ffff888047c32a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888047c32a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888047c32b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


Tested on:

commit: a75cb869 Merge tag 'v7.0-rc1-ksmbd-server-fixes' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1648cd5a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=56150637ffd942dd

dashboard link: https://syzkaller.appspot.com/bug?extid=9ea7c90be2b24e189592
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=16640952580000

[Qing Wang]

#syz test

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c

index 2d14fb6d0ed0..f7a0116c7e46 100644

--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3783,6 +3783,8 @@ static void bpf_raw_tp_link_release(struct bpf_link *link)

bpf_probe_unregister(raw_tp->btp, raw_tp);
bpf_put_raw_tracepoint(raw_tp->btp);
+

+ tracepoint_synchronize_unregister();

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:

lost connection to test machine

Tested on:

commit: a75cb869 Merge tag 'v7.0-rc1-ksmbd-server-fixes' of gi..
git tree: upstream

console output: https://syzkaller.appspot.com/x/log.txt?x=12e650ba580000

kernel config: https://syzkaller.appspot.com/x/.config?x=56150637ffd942dd
dashboard link: https://syzkaller.appspot.com/bug?extid=9ea7c90be2b24e189592
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=1476755a580000

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 2f9339c052bd Merge tag 'spi-fix-v7.0-rc1' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1610e3e6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=56150637ffd942dd

dashboard link: https://syzkaller.appspot.com/bug?extid=9ea7c90be2b24e189592
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b12d5a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153ce006580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-2f9339c0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/03f5cd2356a3/vmlinux-2f9339c0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fd9f61ab139e/bzImage-2f9339c0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9ea7c9...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
BUG: KASAN: slab-use-after-free in bpf_trace_run3+0xdd/0x850 kernel/trace/bpf_trace.c:2130

Read of size 8 at addr ffff88803828ab18 by task dhcpcd-run-hook/5487

CPU: 0 UID: 0 PID: 5487 Comm: dhcpcd-run-hook 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_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:2075 [inline]
bpf_trace_run3+0xdd/0x850 kernel/trace/bpf_trace.c:2130

__traceiter_kmem_cache_free+0x38/0x60 include/trace/events/kmem.h:117
__do_trace_kmem_cache_free include/trace/events/kmem.h:117 [inline]
trace_kmem_cache_free include/trace/events/kmem.h:117 [inline]
kmem_cache_free+0x5ac/0x630 mm/slub.c:6272
anon_vma_chain_free mm/rmap.c:147 [inline]
unlink_anon_vmas+0x69d/0x730 mm/rmap.c:532
free_pgtables+0x836/0xb70 mm/memory.c:427
exit_mmap+0x490/0xa10 mm/mmap.c:1314
__mmput+0x118/0x430 kernel/fork.c:1174
exec_mmap+0x3b4/0x440 fs/exec.c:893
begin_new_exec+0x134a/0x24a0 fs/exec.c:1148
load_elf_binary+0xa47/0x2980 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1664 [inline]
exec_binprm fs/exec.c:1696 [inline]
bprm_execve+0x93d/0x1460 fs/exec.c:1748
do_execveat_common+0x50d/0x690 fs/exec.c:1846
__do_sys_execve fs/exec.c:1930 [inline]
__se_sys_execve fs/exec.c:1924 [inline]
__x64_sys_execve+0x97/0xc0 fs/exec.c:1924

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

RIP: 0033:0x7f4dd469a107
Code: Unable to access opcode bytes at 0x7f4dd469a0dd.
RSP: 002b:00007ffed1452c68 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055b1f84170c8 RCX: 00007f4dd469a107
RDX: 000055b1f84170e8 RSI: 000055b1f84170c8 RDI: 000055b1f8417170
RBP: 000055b1f8417170 R08: 00007ffed1456ea4 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 000055b1f84170e8
R13: 00007f4dd485fe8b R14: 000055b1f84170e8 R15: 0000000000000000
</TASK>

Allocated by task 5486:

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 15:

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

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

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

exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x69b/0x2320 kernel/exit.c:971
do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232

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

The buggy address belongs to the object at ffff88803828ab00

which belongs to the cache kmalloc-192 of size 192
The buggy address is located 24 bytes inside of

freed 192-byte region [ffff88803828ab00, ffff88803828abc0)

The buggy address belongs to the physical page:

page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803828a100 pfn:0x3828a

flags: 0x4fff00000000200(workingset|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)

raw: 04fff00000000200 ffff88801ac413c0 ffff888030400288 ffffea0000e19390
raw: ffff88803828a100 000000080010000e 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 0xd2c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 22245651735, free_ts 22245107019

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]
__do_kmalloc_node mm/slub.c:5237 [inline]
__kmalloc_noprof+0x474/0x760 mm/slub.c:5250
kmalloc_noprof include/linux/slab.h:954 [inline]
usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75
usb_internal_control_msg drivers/usb/core/message.c:96 [inline]
usb_control_msg+0x118/0x3e0 drivers/usb/core/message.c:154
usb_control_msg_send drivers/usb/core/message.c:214 [inline]
usb_set_configuration+0x127a/0x2110 drivers/usb/core/message.c:2149
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291

call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:661
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:803

driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
__device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961
page last free pid 30 tgid 30 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

__kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
__kasan_populate_vmalloc+0x1b2/0x1d0 mm/kasan/shadow.c:424
kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
alloc_vmap_area+0xd73/0x14b0 mm/vmalloc.c:2129
__get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3232
__vmalloc_node_range_noprof+0x372/0x1730 mm/vmalloc.c:4024
__vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124
alloc_thread_stack_node kernel/fork.c:355 [inline]
dup_task_struct+0x228/0x9a0 kernel/fork.c:924
copy_process+0x508/0x3cf0 kernel/fork.c:2050
kernel_clone+0x248/0x8e0 kernel/fork.c:2654
user_mode_thread+0x110/0x180 kernel/fork.c:2730
call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171

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

Memory state around the buggy address:

ffff88803828aa00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803828aa80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88803828ab00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88803828ab80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff88803828ac00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---

[Qing Wang]

#syz test

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c

index 0378e83b4099..b1e3e9f59930 100644

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+9ea7c9...@syzkaller.appspotmail.com
Tested-by: syzbot+9ea7c9...@syzkaller.appspotmail.com

Tested on:

commit: 0031c068 Merge tag 'cgroup-for-7.0-rc2-fixes' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12afb006580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5c49ee0942d1cdb

dashboard link: https://syzkaller.appspot.com/bug?extid=9ea7c90be2b24e189592
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

patch: https://syzkaller.appspot.com/x/patch.diff?x=1566e552580000

Note: testing is done by a robot and is best-effort only.

[Qing Wang]

It's same as [0].
[0] https://syzkaller.appspot.com/bug?extid=b4c5ad098c821bf8d8bc

I sent the fixed patch [1] to [0].
[1] https://lore.kernel.org/all/20260304070927.178...@gmail.com/T/

--
Qing