================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in refcount_inc_not_zero_checked+0x3d/0x200 lib/refcount.c:123 Read of size 4 at addr ffff888090401080 by task syz-executor.2/21190 CPU: 0 PID: 21190 Comm: syz-executor.2 Not tainted 5.4.0-rc4+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113 print_address_description+0x75/0x5c0 mm/kasan/report.c:374 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506 kasan_report+0x26/0x50 mm/kasan/common.c:634 check_memory_region_inline mm/kasan/generic.c:182 [inline] check_memory_region+0x2cf/0x2e0 mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 mm/kasan/common.c:92 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] refcount_inc_not_zero_checked+0x3d/0x200 lib/refcount.c:123 refcount_inc_checked+0x15/0x50 lib/refcount.c:156 sock_hold include/net/sock.h:649 [inline] nr_release+0x59/0x390 net/netrom/af_netrom.c:520 __sock_release net/socket.c:590 [inline] sock_close+0xe1/0x260 net/socket.c:1268 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413ad1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffcb5829610 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000413ad1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: 000000003ae0e68f R09: 000000003ae0e693 R10: 00007ffcb58296f0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000760a80 R15: 000000000075c07c Allocated by task 21200: save_stack mm/kasan/common.c:69 [inline] set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x254/0x340 mm/slab.c:3664 kmalloc include/linux/slab.h:561 [inline] sk_prot_alloc+0xb0/0x290 net/core/sock.c:1605 sk_alloc+0x38/0x950 net/core/sock.c:1659 nr_create+0xa7/0x510 net/netrom/af_netrom.c:433 __sock_create+0x5cc/0x910 net/socket.c:1418 sock_create net/socket.c:1469 [inline] __sys_socket+0xe7/0x2e0 net/socket.c:1511 __do_sys_socket net/socket.c:1520 [inline] __se_sys_socket net/socket.c:1518 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1518 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21190: save_stack mm/kasan/common.c:69 [inline] set_track mm/kasan/common.c:77 [inline] kasan_set_free_info mm/kasan/common.c:332 [inline] __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480 __cache_free mm/slab.c:3425 [inline] kfree+0x115/0x200 mm/slab.c:3756 sk_prot_free net/core/sock.c:1642 [inline] __sk_destruct+0x523/0x620 net/core/sock.c:1726 sk_destruct net/core/sock.c:1741 [inline] __sk_free+0x35d/0x430 net/core/sock.c:1752 sk_free+0x2a/0x40 net/core/sock.c:1763 sock_put include/net/sock.h:1730 [inline] nr_release+0x1d2/0x390 net/netrom/af_netrom.c:554 __sock_release net/socket.c:590 [inline] sock_close+0xe1/0x260 net/socket.c:1268 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888090401000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff888090401000, ffff888090401800) The buggy address belongs to the page: page:ffffea0002410040 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002619088 ffffea0001649948 ffff8880aa400e00 raw: 0000000000000000 ffff888090401000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888090400f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090401000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888090401080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888090401100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888090401180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================