Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 5832 Comm: syz-executor Not tainted 6.16.0-rc2-next-20250620-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162 Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 67 19 de ff 49 83 3e 00 0f 85 84 00 00 00 e8 78 ee 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 42 19 de ff 4c 8b 33 4d 85 f6 74 RSP: 0018:ffffc90000007c30 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88803230da00 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff8880285e4970 RBP: 0000000000000001 R08: ffff8880285e4903 R09: 1ffff110050bc920 R10: dffffc0000000000 R11: ffffed10050bc921 R12: 1ffff110050bc92d R13: ffffffff81a8bfb4 R14: ffff8880285e4968 R15: dffffc0000000000 FS: 00005555572ff500(0000) GS:ffff888125c26000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb940ee56c0 CR3: 000000007e74c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: put_pid+0x9c/0x130 kernel/pid.c:103 rcu_do_batch kernel/rcu/tree.c:2582 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2838 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 lock_sock include/net/sock.h:1667 [inline] tcp_sendmsg+0x21/0x50 net/ipv4/tcp.c:1395 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x19c/0x270 net/socket.c:727 sock_write_iter+0x258/0x330 net/socket.c:1177 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f412578d3a0 Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d a1 81 1f 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89 RSP: 002b:00007ffc60e056c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000d9f96440 RCX: 00007f412578d3a0 RDX: 0000000000000100 RSI: 00007f412323ff00 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000007 R09: 000000000003fde8 R10: 711b6c0f8f946bb3 R11: 0000000000000202 R12: 0000000000000100 R13: 00005555573185c0 R14: 00007ffc60e05b90 R15: 00007f412323ff00 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:pidfs_free_pid+0xaf/0x140 fs/pidfs.c:162 Code: f0 ff ff 73 e4 43 80 3c 3c 00 74 08 4c 89 f7 e8 67 19 de ff 49 83 3e 00 0f 85 84 00 00 00 e8 78 ee 79 ff 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 42 19 de ff 4c 8b 33 4d 85 f6 74 RSP: 0018:ffffc90000007c30 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88803230da00 RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff8880285e4970 RBP: 0000000000000001 R08: ffff8880285e4903 R09: 1ffff110050bc920 R10: dffffc0000000000 R11: ffffed10050bc921 R12: 1ffff110050bc92d R13: ffffffff81a8bfb4 R14: ffff8880285e4968 R15: dffffc0000000000 FS: 00005555572ff500(0000) GS:ffff888125c26000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb940ee56c0 CR3: 000000007e74c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: f0 ff lock (bad) 2: ff 73 e4 push -0x1c(%rbx) 5: 43 80 3c 3c 00 cmpb $0x0,(%r12,%r15,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 67 19 de ff call 0xffde197b 14: 49 83 3e 00 cmpq $0x0,(%r14) 18: 0f 85 84 00 00 00 jne 0xa2 1e: e8 78 ee 79 ff call 0xff79ee9b 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 42 19 de ff call 0xffde197b 39: 4c 8b 33 mov (%rbx),%r14 3c: 4d 85 f6 test %r14,%r14 3f: 74 .byte 0x74