================================================================== 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:1078 [inline] BUG: KASAN: use-after-free in consume_skb+0x2e/0x160 net/core/skbuff.c:908 Read of size 4 at addr ffff8880791840dc by task syz-executor.2/13730 CPU: 0 PID: 13730 Comm: syz-executor.2 Not tainted 5.16.0-rc1-next-20211117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 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:1078 [inline] consume_skb+0x2e/0x160 net/core/skbuff.c:908 __sk_msg_free+0x26d/0x360 net/core/skmsg.c:196 sk_msg_free net/core/skmsg.c:209 [inline] __sk_psock_purge_ingress_msg net/core/skmsg.c:748 [inline] __sk_psock_zap_ingress net/core/skmsg.c:766 [inline] sk_psock_stop+0x415/0x620 net/core/skmsg.c:784 sock_map_close+0x34a/0x780 net/core/sock_map.c:1510 unix_release+0x7a/0xe0 net/unix/af_unix.c:944 __sock_release+0xcd/0x280 net/socket.c:649 sock_close+0x18/0x20 net/socket.c:1314 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f05b467f72b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffd0ed54ca0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007f05b467f72b RDX: 0000000000000000 RSI: ffffffff817e3531 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b2fe26570 R10: 0000000000000076 R11: 0000000000000293 R12: 00007f05b47e0b60 R13: 00007f05b47e0b60 R14: 00007f05b47dff60 R15: 00000000001c0659 Allocated by task 13737: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:3234 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247 skb_clone+0x170/0x3c0 net/core/skbuff.c:1521 sk_psock_verdict_recv+0x72/0x780 net/core/skmsg.c:1157 unix_read_sock+0xd7/0x250 net/unix/af_unix.c:2416 sk_psock_verdict_data_ready+0x11a/0x180 net/core/skmsg.c:1200 unix_dgram_sendmsg+0xfaf/0x1960 net/unix/af_unix.c:1937 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x331/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmmsg+0x195/0x470 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 31804: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kmem_cache_free+0x92/0x5e0 mm/slub.c:3529 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:700 __kfree_skb net/core/skbuff.c:757 [inline] kfree_skb net/core/skbuff.c:774 [inline] kfree_skb+0x140/0x3f0 net/core/skbuff.c:768 sock_drop include/linux/skmsg.h:310 [inline] sk_psock_backlog+0x9de/0xea0 net/core/skmsg.c:668 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888079184000 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 220 bytes inside of 232-byte region [ffff888079184000, ffff8880791840e8) The buggy address belongs to the page: page:ffffea0001e46100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79184 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001ee2d80 dead000000000002 ffff888015596640 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 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 6331, ts 1529675099124, free_ts 1528815270246 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 alloc_slab_page mm/slub.c:1793 [inline] allocate_slab mm/slub.c:1930 [inline] new_slab+0x32d/0x4a0 mm/slub.c:1993 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 slab_alloc_node mm/slub.c:3200 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x35c/0x3a0 mm/slub.c:3247 skb_clone+0x170/0x3c0 net/core/skbuff.c:1521 sk_psock_verdict_recv+0x72/0x780 net/core/skmsg.c:1157 unix_read_sock+0xd7/0x250 net/unix/af_unix.c:2416 sk_psock_verdict_data_ready+0x11a/0x180 net/core/skmsg.c:1200 unix_dgram_sendmsg+0xfaf/0x1960 net/unix/af_unix.c:1937 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x331/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmmsg+0x195/0x470 net/socket.c:2549 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page_list+0x1a9/0xfa0 mm/page_alloc.c:3425 release_pages+0x3f4/0x1480 mm/swap.c:979 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:242 [inline] tlb_flush_mmu mm/mmu_gather.c:249 [inline] tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:340 exit_mmap+0x1ea/0x630 mm/mmap.c:3172 __mmput+0x122/0x4b0 kernel/fork.c:1164 mmput+0x56/0x60 kernel/fork.c:1185 exit_mm kernel/exit.c:507 [inline] do_exit+0xb27/0x2b40 kernel/exit.c:819 do_group_exit+0x125/0x310 kernel/exit.c:929 __do_sys_exit_group kernel/exit.c:940 [inline] __se_sys_exit_group kernel/exit.c:938 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:938 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888079183f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888079184000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888079184080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ^ ffff888079184100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff888079184180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================