==================================================================
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:111 [inline]
BUG: KASAN: use-after-free in kthread_stop+0x32/0x460 kernel/kthread.c:612
Write of size 4 at addr ffff8881eb9b9fa0 by task syz-executor.0/322
CPU: 0 PID: 322 Comm: syz-executor.0 Not tainted 5.4.219-syzkaller-00002-ga0eae55f26a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d8/0x241 lib/dump_stack.c:118
print_address_description+0x8c/0x630 mm/kasan/report.c:384
__kasan_report+0xf6/0x130 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+0x298/0x2d0 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:111 [inline]
kthread_stop+0x32/0x460 kernel/kthread.c:612
ext4_put_super+0x789/0xbc0 fs/ext4/super.c:1055
generic_shutdown_super+0x11b/0x2a0 fs/super.c:464
kill_block_super+0x79/0xd0 fs/super.c:1444
deactivate_locked_super+0xaf/0x100 fs/super.c:335
deactivate_super+0x1b3/0x270 fs/super.c:366
cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102
task_work_run+0x186/0x1b0 kernel/task_work.c:113
ptrace_notify+0x29a/0x340 kernel/signal.c:2271
ptrace_report_syscall include/linux/tracehook.h:66 [inline]
tracehook_report_syscall_exit include/linux/tracehook.h:129 [inline]
syscall_slow_exit_work+0x167/0x3e0 arch/x86/entry/common.c:246
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x19e/0x1c0 arch/x86/entry/common.c:300
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+0x131/0x1e0 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+0xd0/0x210 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/0x5a0 kernel/fork.c:871
copy_process+0x56e/0x3230 kernel/fork.c:1878
_do_fork+0x196/0x8d0 kernel/fork.c:2391
kernel_thread+0x169/0x1d0 kernel/fork.c:2481
create_kthread kernel/kthread.c:311 [inline]
kthreadd+0x3cd/0x520 kernel/kthread.c:654
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Freed by task 299:
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+0x178/0x240 mm/kasan/common.c:487
slab_free_hook mm/slub.c:1455 [inline]
slab_free_freelist_hook+0x80/0x150 mm/slub.c:1494
slab_free mm/slub.c:3080 [inline]
kmem_cache_free+0xa9/0x1d0 mm/slub.c:3096
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x49e/0xa10 kernel/rcu/tree.c:2167
rcu_core+0x4ba/0xca0 kernel/rcu/tree.c:2387
__do_softirq+0x23e/0x643 kernel/softirq.c:292
The buggy address belongs to the object at ffff8881eb9b9f80
which belongs to the cache task_struct of size 3904
The buggy address is located 32 bytes inside of
3904-byte region [ffff8881eb9b9f80, ffff8881eb9baec0)
The buggy address belongs to the page:
page:ffffea0007ae6e00 refcount:1 mapcount:0 mapping:ffff8881f5cecf00 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cecf00
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+0x194/0x380 mm/page_alloc.c:2171
get_page_from_freelist+0x524/0x560 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x372/0x860 mm/page_alloc.c:4891
alloc_slab_page+0x39/0x3e0 mm/slub.c:343
allocate_slab mm/slub.c:1683 [inline]
new_slab+0x97/0x450 mm/slub.c:1749
new_slab_objects mm/slub.c:2505 [inline]
___slab_alloc+0x320/0x4a0 mm/slub.c:2667
__slab_alloc+0x5a/0x90 mm/slub.c:2707
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0x100/0x210 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/0x5a0 kernel/fork.c:871
copy_process+0x56e/0x3230 kernel/fork.c:1878
_do_fork+0x196/0x8d0 kernel/fork.c:2391
kernel_thread+0x169/0x1d0 kernel/fork.c:2481
create_kthread kernel/kthread.c:311 [inline]
kthreadd+0x3cd/0x520 kernel/kthread.c:654
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
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+0x7fe/0x930 mm/page_alloc.c:1438
free_the_page mm/page_alloc.c:4953 [inline]
__free_pages+0x8f/0x250 mm/page_alloc.c:4959
__free_slab+0x22b/0x2e0 mm/slub.c:1774
free_slab mm/slub.c:1789 [inline]
discard_slab mm/slub.c:1795 [inline]
unfreeze_partials+0x14f/0x180 mm/slub.c:2288
put_cpu_partial+0xb5/0x150 mm/slub.c:2324
__slab_free+0x2ac/0x370 mm/slub.c:2971
qlist_free_all+0x4c/0xb0 mm/kasan/quarantine.c:167
quarantine_reduce+0x174/0x190 mm/kasan/quarantine.c:260
__kasan_kmalloc+0x43/0x1e0 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+0xd0/0x210 mm/slub.c:2842
getname_flags+0xb8/0x4e0 fs/namei.c:141
user_path_at_empty+0x28/0x50 fs/namei.c:2683
user_path_at include/linux/namei.h:49 [inline]
vfs_statx+0x120/0x210 fs/stat.c:187
vfs_fstatat include/linux/fs.h:3372 [inline]
__do_sys_newfstatat fs/stat.c:367 [inline]
__se_sys_newfstatat+0xce/0x760 fs/stat.c:361
do_syscall_64+0xcb/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Memory state around the buggy address:
ffff8881eb9b9e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881eb9b9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881eb9b9f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881eb9ba000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881eb9ba080: 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: 0 PID: 322 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 322 Comm: syz-executor.0 Tainted: G B 5.4.219-syzkaller-00002-ga0eae55f26a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
RIP: 0010:refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25
Code: c7 e0 02 fe 84 31 c0 e8 d1 6b 15 ff 0f 0b eb a3 e8 b8 92 3e ff c6 05 88 1c fe 03 01 48 c7 c7 60 03 fe 84 31 c0 e8 b3 6b 15 ff <0f> 0b eb 85 e8 9a 92 3e ff c6 05 6b 1c fe 03 01 48 c7 c7 c0 03 fe
RSP: 0018:ffff8881db637b30 EFLAGS: 00010246
RAX: 6344f1fa90298800 RBX: 0000000000000002 RCX: ffff8881dd6e8fc0
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff814e3a77 R09: 0000000000000003
R10: ffffed103b6c6ee1 R11: 1ffff1103b6c6ee0 R12: dffffc0000000000
R13: ffff8881eb9b9f80 R14: dffffc0000000000 R15: ffff8881eb9b9fa0
FS: 0000555555f6f400(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555f78728 CR3: 00000001db510000 CR4: 00000000003406f0
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:111 [inline]
kthread_stop+0x1a1/0x460 kernel/kthread.c:612
ext4_put_super+0x789/0xbc0 fs/ext4/super.c:1055
generic_shutdown_super+0x11b/0x2a0 fs/super.c:464
kill_block_super+0x79/0xd0 fs/super.c:1444
deactivate_locked_super+0xaf/0x100 fs/super.c:335
deactivate_super+0x1b3/0x270 fs/super.c:366
cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102
task_work_run+0x186/0x1b0 kernel/task_work.c:113
ptrace_notify+0x29a/0x340 kernel/signal.c:2271
ptrace_report_syscall include/linux/tracehook.h:66 [inline]
tracehook_report_syscall_exit include/linux/tracehook.h:129 [inline]
syscall_slow_exit_work+0x167/0x3e0 arch/x86/entry/common.c:246
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x19e/0x1c0 arch/x86/entry/common.c:300
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
---[ end trace 12bfcdf2a939ba1c ]---