==================================================================
BUG: KASAN: use-after-free in atomic_fetch_add include/asm-generic/atomic-instrumented.h:111 [inline]
BUG: KASAN: use-after-free in refcount_add include/linux/refcount.h:188 [inline]
BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:228 [inline]
BUG: KASAN: use-after-free in get_task_struct include/linux/sched/task.h:112 [inline]
BUG: KASAN: use-after-free in kthread_stop+0x37/0x4a0 kernel/kthread.c:612
Write of size 4 at addr ffff8881ed353f20 by task syz-executor.1/466
CPU: 1 PID: 466 Comm: syz-executor.1 Not tainted 5.4.249-syzkaller-00006-gcdfaa21d868e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d8/0x241 lib/dump_stack.c:118
print_address_description+0x8c/0x600 mm/kasan/report.c:384
__kasan_report+0xf3/0x120 mm/kasan/report.c:516
kasan_report+0x30/0x60 mm/kasan/common.c:653
check_memory_region_inline mm/kasan/generic.c:141 [inline]
check_memory_region+0x272/0x280 mm/kasan/generic.c:191
atomic_fetch_add include/asm-generic/atomic-instrumented.h:111 [inline]
refcount_add include/linux/refcount.h:188 [inline]
refcount_inc include/linux/refcount.h:228 [inline]
get_task_struct include/linux/sched/task.h:112 [inline]
kthread_stop+0x37/0x4a0 kernel/kthread.c:612
ext4_put_super+0x7a1/0xbc0 fs/ext4/super.c:1055
generic_shutdown_super+0x120/0x2a0 fs/super.c:464
kill_block_super+0x7a/0xe0 fs/super.c:1444
deactivate_locked_super+0xa8/0x110 fs/super.c:335
deactivate_super+0x1e2/0x2a0 fs/super.c:366
cleanup_mnt+0x44e/0x500 fs/namespace.c:1102
task_work_run+0x140/0x170 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x190/0x1a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Allocated by task 2:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
__kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
slab_post_alloc_hook mm/slab.h:584 [inline]
slab_alloc_node mm/slub.c:2829 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
kmem_cache_alloc_node include/linux/slab.h:427 [inline]
alloc_task_struct_node kernel/fork.c:171 [inline]
dup_task_struct+0x4f/0x600 kernel/fork.c:874
copy_process+0x56d/0x3230 kernel/fork.c:1881
_do_fork+0x197/0x900 kernel/fork.c:2396
kernel_thread+0x16a/0x1d0 kernel/fork.c:2486
create_kthread kernel/kthread.c:311 [inline]
kthreadd+0x3b1/0x4f0 kernel/kthread.c:654
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Freed by task 1060:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
kasan_set_free_info mm/kasan/common.c:345 [inline]
__kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
slab_free_hook mm/slub.c:1455 [inline]
slab_free_freelist_hook mm/slub.c:1494 [inline]
slab_free mm/slub.c:3080 [inline]
kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
__do_softirq+0x23b/0x6b7 kernel/softirq.c:292
The buggy address belongs to the object at ffff8881ed353f00
which belongs to the cache task_struct of size 3904
The buggy address is located 32 bytes inside of
3904-byte region [ffff8881ed353f00, ffff8881ed354e40)
The buggy address belongs to the page:
page:ffffea0007b4d400 refcount:1 mapcount:0 mapping:ffff8881f5cf1180 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cf1180
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook mm/page_alloc.c:2165 [inline]
prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4891
alloc_slab_page+0x39/0x3c0 mm/slub.c:343
allocate_slab mm/slub.c:1683 [inline]
new_slab+0x97/0x440 mm/slub.c:1749
new_slab_objects mm/slub.c:2505 [inline]
___slab_alloc+0x2fe/0x490 mm/slub.c:2667
__slab_alloc+0x62/0xa0 mm/slub.c:2707
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
kmem_cache_alloc_node include/linux/slab.h:427 [inline]
alloc_task_struct_node kernel/fork.c:171 [inline]
dup_task_struct+0x4f/0x600 kernel/fork.c:874
copy_process+0x56d/0x3230 kernel/fork.c:1881
_do_fork+0x197/0x900 kernel/fork.c:2396
__do_sys_clone3 kernel/fork.c:2685 [inline]
__se_sys_clone3 kernel/fork.c:2672 [inline]
__x64_sys_clone3+0x2da/0x300 kernel/fork.c:2672
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1176 [inline]
__free_pages_ok+0x847/0x950 mm/page_alloc.c:1438
free_the_page mm/page_alloc.c:4953 [inline]
__free_pages+0x91/0x140 mm/page_alloc.c:4959
__free_slab+0x221/0x2e0 mm/slub.c:1774
__slab_free+0x34b/0x360 mm/slub.c:3012
qlist_free_all+0x43/0xb0 mm/kasan/quarantine.c:167
quarantine_reduce+0x1d9/0x210 mm/kasan/quarantine.c:260
__kasan_kmalloc+0x41/0x210 mm/kasan/common.c:507
slab_post_alloc_hook mm/slab.h:584 [inline]
slab_alloc_node mm/slub.c:2829 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
getname_flags+0xb8/0x4e0 fs/namei.c:141
user_path_at_empty+0x28/0x50 fs/namei.c:2683
do_readlinkat+0x114/0x3a0 fs/stat.c:398
__do_sys_readlink fs/stat.c:431 [inline]
__se_sys_readlink fs/stat.c:428 [inline]
__x64_sys_readlink+0x7b/0x90 fs/stat.c:428
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Memory state around the buggy address:
ffff8881ed353e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881ed353e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881ed353f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881ed353f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881ed354000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 466 at lib/refcount.c:25 refcount_warn_saturate+0x132/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 466 Comm: syz-executor.1 Tainted: G B 5.4.249-syzkaller-00006-gcdfaa21d868e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
RIP: 0010:refcount_warn_saturate+0x132/0x1a0 lib/refcount.c:25
Code: 04 01 48 c7 c7 e0 f0 f9 84 e8 aa 24 0e ff 0f 0b eb a9 e8 c1 69 37 ff c6 05 23 a9 1c 04 01 48 c7 c7 60 f1 f9 84 e8 8e 24 0e ff <0f> 0b eb 8d e8 a5 69 37 ff c6 05 08 a9 1c 04 01 48 c7 c7 c0 f1 f9
RSP: 0018:ffff8881b63bfc30 EFLAGS: 00010246
RAX: bb06aa8d6ffb8c00 RBX: 0000000000000002 RCX: ffff8881f31faf40
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff814d59f2 R09: ffffed103ede5262
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8881ed353f00 R14: dffffc0000000000 R15: ffff8881ed353f20
FS: 0000555556ee3480(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30632000 CR3: 00000001b6328000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
refcount_add include/linux/refcount.h:192 [inline]
refcount_inc include/linux/refcount.h:228 [inline]
get_task_struct include/linux/sched/task.h:112 [inline]
kthread_stop+0x1a5/0x4a0 kernel/kthread.c:612
ext4_put_super+0x7a1/0xbc0 fs/ext4/super.c:1055
generic_shutdown_super+0x120/0x2a0 fs/super.c:464
kill_block_super+0x7a/0xe0 fs/super.c:1444
deactivate_locked_super+0xa8/0x110 fs/super.c:335
deactivate_super+0x1e2/0x2a0 fs/super.c:366
cleanup_mnt+0x44e/0x500 fs/namespace.c:1102
task_work_run+0x140/0x170 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x190/0x1a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
---[ end trace 441e0277768b40e0 ]---