================================================================== BUG: KASAN: use-after-free in af_alg_accept+0x10d/0x480 crypto/af_alg.c:295 Read of size 8 at addr ffff888055c7f4d0 by task syz-executor.1/16819 CPU: 1 PID: 16819 Comm: syz-executor.1 Not tainted 5.7.0-rc2-syzkaller #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+0x1e9/0x30e lib/dump_stack.c:118 print_address_description+0x74/0x5c0 mm/kasan/report.c:382 __kasan_report+0x103/0x1a0 mm/kasan/report.c:511 kasan_report+0x4d/0x80 mm/kasan/common.c:625 Allocated by task 16819: save_stack mm/kasan/common.c:49 [inline] set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc+0x114/0x160 mm/kasan/common.c:495 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x24b/0x330 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] sk_prot_alloc+0xa7/0x2b0 net/core/sock.c:1604 sk_alloc+0x35/0x990 net/core/sock.c:1658 alg_create+0x9a/0x130 crypto/af_alg.c:373 __sock_create+0x5c9/0x8d0 net/socket.c:1433 sock_create net/socket.c:1484 [inline] __sys_socket+0xde/0x2d0 net/socket.c:1526 __do_sys_socket net/socket.c:1535 [inline] __se_sys_socket net/socket.c:1533 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1533 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 16817: save_stack mm/kasan/common.c:49 [inline] set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0x125/0x190 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 sk_prot_free net/core/sock.c:1641 [inline] __sk_destruct+0x61d/0x740 net/core/sock.c:1725 __sk_destruct+0x50/0x740 net/core/sock.c:1696 sock_put include/net/sock.h:1778 [inline] af_alg_release+0x81/0xf0 crypto/af_alg.c:121 __sock_release net/socket.c:605 [inline] sock_close+0xd8/0x260 net/socket.c:1283 __fput+0x2ed/0x750 fs/file_table.c:280 task_work_run+0x147/0x1d0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:165 [inline] prepare_exit_to_usermode+0x48e/0x600 arch/x86/entry/common.c:196 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff888055c7f000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1232 bytes inside of 2048-byte region [ffff888055c7f000, ffff888055c7f800) The buggy address belongs to the page: page:ffffea0001571fc0 refcount:1 mapcount:0 mapping:000000007e5067b6 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00026415c8 ffffea00028dc208 ffff8880aa400e00 raw: 0000000000000000 ffff888055c7f000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888055c7f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055c7f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888055c7f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888055c7f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055c7f580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================