================================================================== BUG: KASAN: use-after-free in unix_dgram_poll+0x5e1/0x690 net/unix/af_unix.c:2695 Read of size 4 at addr ffff88809292aae0 by task syz-executor.1/18946 CPU: 0 PID: 18946 Comm: syz-executor.1 Not tainted 5.0.0-rc8+ #88 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134 unix_dgram_poll+0x5e1/0x690 net/unix/af_unix.c:2695 sock_poll+0x291/0x340 net/socket.c:1127 vfs_poll include/linux/poll.h:86 [inline] aio_poll fs/aio.c:1766 [inline] __io_submit_one fs/aio.c:1876 [inline] io_submit_one+0xe3e/0x1cf0 fs/aio.c:1909 __do_sys_io_submit fs/aio.c:1954 [inline] __se_sys_io_submit fs/aio.c:1924 [inline] __x64_sys_io_submit+0x1bd/0x580 fs/aio.c:1924 ? 0xffffffff81000000 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd43ca93c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e29 RDX: 0000000020000600 RSI: 1ffffffffffffd70 RDI: 00007fd43ca73000 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd43ca946d4 R13: 00000000004bf02f R14: 00000000004d09b0 R15: 00000000ffffffff Allocated by task 18946: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:503 slab_post_alloc_hook mm/slab.h:440 [inline] slab_alloc mm/slab.c:3388 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3548 sk_prot_alloc+0x67/0x2e0 net/core/sock.c:1471 sk_alloc+0x39/0xf70 net/core/sock.c:1531 unix_create1+0xc3/0x530 net/unix/af_unix.c:764 unix_create+0x103/0x1e0 net/unix/af_unix.c:825 __sock_create+0x3e6/0x750 net/socket.c:1275 sock_create net/socket.c:1315 [inline] __sys_socketpair+0x272/0x5e0 net/socket.c:1407 __do_sys_socketpair net/socket.c:1456 [inline] __se_sys_socketpair net/socket.c:1453 [inline] __x64_sys_socketpair+0x97/0xf0 net/socket.c:1453 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 18944: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:457 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465 __cache_free mm/slab.c:3494 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3754 sk_prot_free net/core/sock.c:1512 [inline] __sk_destruct+0x4b6/0x6d0 net/core/sock.c:1596 sk_destruct+0x7b/0x90 net/core/sock.c:1604 __sk_free+0xce/0x300 net/core/sock.c:1615 sk_free+0x42/0x50 net/core/sock.c:1626 sock_put include/net/sock.h:1707 [inline] unix_release_sock+0x921/0xbb0 net/unix/af_unix.c:573 unix_release+0x44/0x90 net/unix/af_unix.c:835 __sock_release+0xd3/0x250 net/socket.c:579 sock_close+0x1b/0x30 net/socket.c:1139 __fput+0x2df/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88809292a740 which belongs to the cache UNIX(49:syz1) of size 1728 The buggy address is located 928 bytes inside of 1728-byte region [ffff88809292a740, ffff88809292ae00) The buggy address belongs to the page: page:ffffea00024a4a80 count:1 mapcount:0 mapping:ffff8880920c0800 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00028223c8 ffffea0002581248 ffff8880920c0800 raw: 0000000000000000 ffff88809292a000 0000000100000002 ffff8880a9718ec0 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8880a9718ec0 Memory state around the buggy address: ffff88809292a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809292aa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809292aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809292ab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809292ab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================