==================================================================
BUG: KASAN: slab-use-after-free in lec_arp_clear_vccs+0x6c/0x380 net/atm/lec.c:1260
Read of size 8 at addr ffff88802b3766d0 by task syz.8.12365/19843
CPU: 0 UID: 0 PID: 19843 Comm: syz.8.12365 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0xe8/0x150 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
lec_arp_clear_vccs+0x6c/0x380 net/atm/lec.c:1260
lec_arp_expire_vcc+0x17d/0x370 net/atm/lec.c:1598
call_timer_fn+0x16e/0x590 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2373 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2385
run_timer_base kernel/time/timer.c:2394 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2404
handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x60/0x150 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
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:260 [inline]
RIP: 0010:rb_erase+0x9c/0xe60 lib/rbtree.c:443
Code: 82 01 00 00 49 8d 5f 10 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 97 f5 d1 f6 48 8b 03 <48> 85 c0 4c 89 6c 24 10 0f 84 e0 01 00 00 4c 89 7c 24 08 4d 89 fc
RSP: 0018:ffffc90010e9f858 EFLAGS: 00000246
RAX: ffff88807d3137c0 RBX: ffff8880b0429c80 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: ffff8880a2b6eac0 RDI: ffff888038919048
RBP: 1ffff1100712320a R08: ffff88801bef01b7 R09: 1ffff110037de036
R10: dffffc0000000000 R11: ffffed10037de037 R12: ffff8880274bb310
R13: ffff888038919040 R14: ffff888038919050 R15: ffff8880b0429c70
kernfs_unlink_sibling+0x12b/0x180 fs/kernfs/dir.c:430
__kernfs_remove+0x3d4/0x650 fs/kernfs/dir.c:1519
kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files fs/sysfs/group.c:28 [inline]
sysfs_remove_group+0xfc/0x2f0 fs/sysfs/group.c:328
sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352
destroy_gid_attrs drivers/infiniband/core/sysfs.c:1182 [inline]
ib_free_port_attrs+0xc5/0x3b0 drivers/infiniband/core/sysfs.c:1407
remove_one_compat_dev drivers/infiniband/core/device.c:1038 [inline]
rdma_dev_exit_net+0x1d8/0x340 drivers/infiniband/core/device.c:1176
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
setup_net+0x2e8/0x330 net/core/net_namespace.c:462
copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581
create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:226
ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3171
__do_sys_unshare kernel/fork.c:3242 [inline]
__se_sys_unshare kernel/fork.c:3240 [inline]
__x64_sys_unshare+0x38/0x50 kernel/fork.c:3240
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f053218f749
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:00007f0532fe7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f05323e5fa0 RCX: 00007f053218f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000068040200
RBP: 00007f0532213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f05323e6038 R14: 00007f05323e5fa0 R15: 00007fff88b7b1e8
Allocated by task 19482:
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]
__do_kmalloc_node mm/slub.c:5657 [inline]
__kmalloc_noprof+0x41d/0x800 mm/slub.c:5669
kmalloc_noprof include/linux/slab.h:961 [inline]
tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822
tomoyo_path_symlink+0xa3/0xe0 security/tomoyo/tomoyo.c:212
security_path_symlink+0x177/0x380 security/security.c:1476
do_symlinkat+0x15d/0x3c0 fs/namei.c:5539
__do_sys_symlinkat fs/namei.c:5562 [inline]
__se_sys_symlinkat fs/namei.c:5559 [inline]
__x64_sys_symlinkat+0x95/0xb0 fs/namei.c:5559
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 19482:
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:2540 [inline]
slab_free mm/slub.c:6670 [inline]
kfree+0x1c0/0x660 mm/slub.c:6878
tomoyo_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822
tomoyo_path_symlink+0xa3/0xe0 security/tomoyo/tomoyo.c:212
security_path_symlink+0x177/0x380 security/security.c:1476
do_symlinkat+0x15d/0x3c0 fs/namei.c:5539
__do_sys_symlinkat fs/namei.c:5562 [inline]
__se_sys_symlinkat fs/namei.c:5559 [inline]
__x64_sys_symlinkat+0x95/0xb0 fs/namei.c:5559
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802b376000
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1744 bytes inside of
freed 4096-byte region [ffff88802b376000, ffff88802b377000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b370
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ffa7140 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ffa7140 0000000000000000 dead000000000001
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000acdc01 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 11068, tgid 11058 (syz.8.9777), ts 2085380300805, free_ts 2083805064994
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [inline]
get_page_from_freelist+0x24e0/0x2580 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+0xe53/0x1820 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]
tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723
security_file_ioctl+0xcb/0x2d0 security/security.c:2435
__do_sys_ioctl fs/ioctl.c:591 [inline]
__se_sys_ioctl+0x47/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 7543 tgid 7543 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
__slab_free+0x2ce/0x320 mm/slub.c:6004
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:350
kasan_slab_alloc include/linux/kasan.h:253 [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
anon_vma_alloc mm/rmap.c:93 [inline]
anon_vma_fork+0xde/0x500 mm/rmap.c:359
dup_mmap+0x954/0x1b80 mm/mmap.c:1790
dup_mm kernel/fork.c:1529 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1581
copy_process+0x165d/0x3950 kernel/fork.c:2221
kernel_clone+0x21e/0x820 kernel/fork.c:2651
__do_sys_clone kernel/fork.c:2792 [inline]
__se_sys_clone kernel/fork.c:2776 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff88802b376580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802b376600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802b376680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802b376700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802b376780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 00 00 add %al,(%rax)
2: 49 8d 5f 10 lea 0x10(%r15),%rbx
6: 48 89 d8 mov %rbx,%rax
9: 48 c1 e8 03 shr $0x3,%rax
d: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
14: fc ff df
17: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1)
1b: 74 08 je 0x25
1d: 48 89 df mov %rbx,%rdi
20: e8 97 f5 d1 f6 call 0xf6d1f5bc
25: 48 8b 03 mov (%rbx),%rax
* 28: 48 85 c0 test %rax,%rax <-- trapping instruction
2b: 4c 89 6c 24 10 mov %r13,0x10(%rsp)
30: 0f 84 e0 01 00 00 je 0x216
36: 4c 89 7c 24 08 mov %r15,0x8(%rsp)
3b: 4d 89 fc mov %r15,%r12