==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:147 [inline]
BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:1131 [inline]
BUG: KASAN: use-after-free in consume_skb+0x3a/0x1f0 net/core/skbuff.c:926
Read of size 4 at addr ffff8881231a99ac by task syz-executor.0/337

CPU: 1 PID: 337 Comm: syz-executor.0 Not tainted 5.15.182-syzkaller-1080481-g57725b368731 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0xf1/0x140 mm/kasan/report.c:444
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x280/0x290 mm/kasan/generic.c:189
 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
 refcount_read include/linux/refcount.h:147 [inline]
 skb_unref include/linux/skbuff.h:1131 [inline]
 consume_skb+0x3a/0x1f0 net/core/skbuff.c:926
 __sk_msg_free+0x4f4/0x560 net/core/skmsg.c:205
 sk_msg_free net/core/skmsg.c:218 [inline]
 __sk_psock_purge_ingress_msg net/core/skmsg.c:773 [inline]
 __sk_psock_zap_ingress net/core/skmsg.c:791 [inline]
 sk_psock_stop+0x4c9/0x570 net/core/skmsg.c:809
 sk_psock_drop+0x226/0x300 net/core/skmsg.c:848
 sk_psock_put include/linux/skmsg.h:463 [inline]
 sock_map_unref+0x3c2/0x420 net/core/sock_map.c:184
 __sock_map_delete net/core/sock_map.c:425 [inline]
 sock_map_delete_from_link net/core/sock_map.c:438 [inline]
 sock_map_unlink net/core/sock_map.c:1497 [inline]
 sock_map_remove_links+0x3cd/0x600 net/core/sock_map.c:1512
 sock_map_close+0x111/0x440 net/core/sock_map.c:1549
 unix_release+0x82/0xc0 net/unix/af_unix.c:936
 __sock_release net/socket.c:649 [inline]
 sock_close+0xe0/0x270 net/socket.c:1336
 __fput+0x20b/0x8b0 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4a9a517c9a
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24
RSP: 002b:00007fff5317ff00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f4a9a517c9a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f4a9a649980 R08: 0000001b30360000 R09: 00036cf8771a4ff4
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000b5dc
R13: ffffffffffffffff R14: 00007f4a9a09c000 R15: 000000000000b29b
 </TASK>

Allocated by task 338:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:433 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466
 kasan_slab_alloc include/linux/kasan.h:217 [inline]
 slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
 slab_alloc_node mm/slub.c:3240 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 kmem_cache_alloc+0xf7/0x260 mm/slub.c:3255
 skb_clone+0x1cf/0x360 net/core/skbuff.c:1547
 sk_psock_verdict_recv+0x53/0x800 net/core/skmsg.c:1187
 unix_read_sock+0x10a/0x2c0 net/unix/af_unix.c:2428
 sk_psock_verdict_data_ready+0x115/0x170 net/core/skmsg.c:1230
 unix_dgram_sendmsg+0x11e6/0x1880 net/unix/af_unix.c:1942
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmmsg+0x278/0x480 net/socket.c:2576
 __do_sys_sendmmsg net/socket.c:2605 [inline]
 __se_sys_sendmmsg net/socket.c:2602 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2602
 x64_sys_call+0x6c6/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 287:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749
 slab_free mm/slub.c:3521 [inline]
 kmem_cache_free+0x100/0x320 mm/slub.c:3539
 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:758 [inline]
 kfree_skb_reason net/core/skbuff.c:778 [inline]
 kfree_skb+0xc1/0x2f0 net/core/skbuff.c:792
 sock_drop include/linux/skmsg.h:312 [inline]
 sk_psock_backlog+0xa85/0xd80 net/core/skmsg.c:684
 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325
 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472
 kthread+0x411/0x500 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff8881231a98c0
 which belongs to the cache skbuff_head_cache of size 248
The buggy address is located 236 bytes inside of
 248-byte region [ffff8881231a98c0, ffff8881231a99b8)
The buggy address belongs to the page:
page:ffffea00048c6a40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1231a9
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881081aa480
raw: 0000000000000000 00000000000c000c 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 90, ts 45733941353, free_ts 44796617170
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611
 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485
 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5781
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1932 [inline]
 new_slab+0xa1/0x4d0 mm/slub.c:1995
 ___slab_alloc+0x381/0x810 mm/slub.c:3028
 __slab_alloc+0x49/0x90 mm/slub.c:3115
 slab_alloc_node mm/slub.c:3206 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 kmem_cache_alloc+0x138/0x260 mm/slub.c:3255
 kmem_cache_alloc_node include/linux/slab.h:489 [inline]
 __alloc_skb+0xe0/0x740 net/core/skbuff.c:416
 alloc_skb include/linux/skbuff.h:1183 [inline]
 alloc_skb_with_frags+0xa8/0x620 net/core/skbuff.c:6194
 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2537
 unix_dgram_sendmsg+0x5ea/0x1880 net/unix/af_unix.c:1805
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 __sys_sendto+0x423/0x580 net/socket.c:2063
 __do_sys_sendto net/socket.c:2075 [inline]
 __se_sys_sendto net/socket.c:2071 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2071
 x64_sys_call+0x178/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1472 [inline]
 free_pcp_prepare mm/page_alloc.c:1544 [inline]
 free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534
 free_unref_page+0xa2/0x550 mm/page_alloc.c:3616
 free_the_page mm/page_alloc.c:805 [inline]
 __free_pages+0x6c/0x100 mm/page_alloc.c:5857
 __vunmap+0x84d/0x9e0 mm/vmalloc.c:2652
 __vfree mm/vmalloc.c:2701 [inline]
 vfree+0x8b/0xc0 mm/vmalloc.c:2732
 kcov_put kernel/kcov.c:417 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:519
 __fput+0x20b/0x8b0 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff8881231a9880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
 ffff8881231a9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881231a9980: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
                                  ^
 ffff8881231a9a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881231a9a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
==================================================================
==================================================================
BUG: KASAN: double-free or invalid-free in slab_free mm/slub.c:3521 [inline]
BUG: KASAN: double-free or invalid-free in kmem_cache_free+0x100/0x320 mm/slub.c:3539

CPU: 1 PID: 337 Comm: syz-executor.0 Tainted: G    B             5.15.182-syzkaller-1080481-g57725b368731 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 kasan_report_invalid_free+0x58/0x90 mm/kasan/report.c:370
 ____kasan_slab_free+0x13d/0x160 mm/kasan/common.c:-1
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749
 slab_free mm/slub.c:3521 [inline]
 kmem_cache_free+0x100/0x320 mm/slub.c:3539
 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:758 [inline]
 consume_skb+0xb3/0x1f0 net/core/skbuff.c:930
 __sk_msg_free+0x4f4/0x560 net/core/skmsg.c:205
 sk_msg_free net/core/skmsg.c:218 [inline]
 __sk_psock_purge_ingress_msg net/core/skmsg.c:773 [inline]
 __sk_psock_zap_ingress net/core/skmsg.c:791 [inline]
 sk_psock_stop+0x4c9/0x570 net/core/skmsg.c:809
 sk_psock_drop+0x226/0x300 net/core/skmsg.c:848
 sk_psock_put include/linux/skmsg.h:463 [inline]
 sock_map_unref+0x3c2/0x420 net/core/sock_map.c:184
 __sock_map_delete net/core/sock_map.c:425 [inline]
 sock_map_delete_from_link net/core/sock_map.c:438 [inline]
 sock_map_unlink net/core/sock_map.c:1497 [inline]
 sock_map_remove_links+0x3cd/0x600 net/core/sock_map.c:1512
 sock_map_close+0x111/0x440 net/core/sock_map.c:1549
 unix_release+0x82/0xc0 net/unix/af_unix.c:936
 __sock_release net/socket.c:649 [inline]
 sock_close+0xe0/0x270 net/socket.c:1336
 __fput+0x20b/0x8b0 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4a9a517c9a
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24
RSP: 002b:00007fff5317ff00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f4a9a517c9a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f4a9a649980 R08: 0000001b30360000 R09: 00036cf8771a4ff4
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000b5dc
R13: ffffffffffffffff R14: 00007f4a9a09c000 R15: 000000000000b29b
 </TASK>

Allocated by task 338:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:433 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466
 kasan_slab_alloc include/linux/kasan.h:217 [inline]
 slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
 slab_alloc_node mm/slub.c:3240 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 kmem_cache_alloc+0xf7/0x260 mm/slub.c:3255
 skb_clone+0x1cf/0x360 net/core/skbuff.c:1547
 sk_psock_verdict_recv+0x53/0x800 net/core/skmsg.c:1187
 unix_read_sock+0x10a/0x2c0 net/unix/af_unix.c:2428
 sk_psock_verdict_data_ready+0x115/0x170 net/core/skmsg.c:1230
 unix_dgram_sendmsg+0x11e6/0x1880 net/unix/af_unix.c:1942
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmmsg+0x278/0x480 net/socket.c:2576
 __do_sys_sendmmsg net/socket.c:2605 [inline]
 __se_sys_sendmmsg net/socket.c:2602 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2602
 x64_sys_call+0x6c6/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 287:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749
 slab_free mm/slub.c:3521 [inline]
 kmem_cache_free+0x100/0x320 mm/slub.c:3539
 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:758 [inline]
 kfree_skb_reason net/core/skbuff.c:778 [inline]
 kfree_skb+0xc1/0x2f0 net/core/skbuff.c:792
 sock_drop include/linux/skmsg.h:312 [inline]
 sk_psock_backlog+0xa85/0xd80 net/core/skmsg.c:684
 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325
 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472
 kthread+0x411/0x500 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff8881231a98c0
 which belongs to the cache skbuff_head_cache of size 248
The buggy address is located 0 bytes inside of
 248-byte region [ffff8881231a98c0, ffff8881231a99b8)
The buggy address belongs to the page:
page:ffffea00048c6a40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1231a9
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881081aa480
raw: 0000000000000000 00000000000c000c 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 90, ts 45733941353, free_ts 44796617170
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611
 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485
 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5781
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1932 [inline]
 new_slab+0xa1/0x4d0 mm/slub.c:1995
 ___slab_alloc+0x381/0x810 mm/slub.c:3028
 __slab_alloc+0x49/0x90 mm/slub.c:3115
 slab_alloc_node mm/slub.c:3206 [inline]
 slab_alloc mm/slub.c:3250 [inline]
 kmem_cache_alloc+0x138/0x260 mm/slub.c:3255
 kmem_cache_alloc_node include/linux/slab.h:489 [inline]
 __alloc_skb+0xe0/0x740 net/core/skbuff.c:416
 alloc_skb include/linux/skbuff.h:1183 [inline]
 alloc_skb_with_frags+0xa8/0x620 net/core/skbuff.c:6194
 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2537
 unix_dgram_sendmsg+0x5ea/0x1880 net/unix/af_unix.c:1805
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 __sys_sendto+0x423/0x580 net/socket.c:2063
 __do_sys_sendto net/socket.c:2075 [inline]
 __se_sys_sendto net/socket.c:2071 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2071
 x64_sys_call+0x178/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1472 [inline]
 free_pcp_prepare mm/page_alloc.c:1544 [inline]
 free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534
 free_unref_page+0xa2/0x550 mm/page_alloc.c:3616
 free_the_page mm/page_alloc.c:805 [inline]
 __free_pages+0x6c/0x100 mm/page_alloc.c:5857
 __vunmap+0x84d/0x9e0 mm/vmalloc.c:2652
 __vfree mm/vmalloc.c:2701 [inline]
 vfree+0x8b/0xc0 mm/vmalloc.c:2732
 kcov_put kernel/kcov.c:417 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:519
 __fput+0x20b/0x8b0 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff8881231a9780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881231a9800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
>ffff8881231a9880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                                           ^
 ffff8881231a9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881231a9980: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
==================================================================