------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 10194 at lib/refcount.c:25 refcount_warn_saturate+0xdd/0x140 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 10194 Comm: syz-executor.0 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_warn_saturate+0xdd/0x140 lib/refcount.c:25 Code: f3 2a e4 08 01 e8 7f f1 9b 04 0f 0b eb 9d 80 3d e2 2a e4 08 00 75 94 48 c7 c7 c0 22 1f 89 c6 05 d2 2a e4 08 01 e8 5f f1 9b 04 <0f> 0b e9 7a ff ff ff 80 3d bc 2a e4 08 00 0f 85 6d ff ff ff 48 c7 RSP: 0018:ffffc9000a7bff10 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffffffff8f38fd80 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000004 RDI: fffff520014f7fd4 RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8880b9e1fa9b R10: ffffed10173c3f53 R11: 746e756f63666572 R12: ffffc9000a7bff58 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fc5e54d6700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f87a7a27000 CR3: 000000004da48000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:199 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] __do_sys_memfd_secret mm/secretmem.c:221 [inline] __se_sys_memfd_secret mm/secretmem.c:194 [inline] __x64_sys_memfd_secret+0xe1/0x140 mm/secretmem.c:194 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 RIP: 0033:0x7fc5e5d60a39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc5e54d6188 EFLAGS: 00000246 ORIG_RAX: 00000000000001bf RAX: ffffffffffffffda RBX: 00007fc5e5e63f60 RCX: 00007fc5e5d60a39 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc5e5dbae8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffca597c8af R14: 00007fc5e54d6300 R15: 0000000000022000