------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 10161 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 10161 Comm: syz-executor.5 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Code: c7 80 e1 b3 8a 31 c0 e8 31 8e 3b fd 0f 0b eb a3 e8 b8 79 71 fd c6 05 43 86 b6 09 01 48 c7 c7 e0 e1 b3 8a 31 c0 e8 13 8e 3b fd <0f> 0b eb 85 e8 9a 79 71 fd c6 05 26 86 b6 09 01 48 c7 c7 40 e2 b3 RSP: 0018:ffffc9000c05fed0 EFLAGS: 00010246 RAX: 1eba0793bac31200 RBX: 0000000000000002 RCX: 0000000000040000 RDX: ffffc900142ec000 RSI: 00000000000039d1 RDI: 00000000000039d2 RBP: 0000000000000002 R08: ffffffff81695fe2 R09: ffffed10173a57a8 R10: ffffed10173a57a8 R11: 0000000000000000 R12: ffff88801d5bd180 R13: ffff888090684f60 R14: 0000000000000003 R15: dffffc0000000000 FS: 00007f9d28a29700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2da23000 CR3: 0000000070ba9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __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+0x2ea/0x350 mm/secretmem.c:194 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9d2b4d4a39 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:00007f9d28a29188 EFLAGS: 00000246 ORIG_RAX: 00000000000001bf RAX: ffffffffffffffda RBX: 00007f9d2b5d8020 RCX: 00007f9d2b4d4a39 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f9d2b52ee8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdbd5583ef R14: 00007f9d28a29300 R15: 0000000000022000