WARNING: CPU: 0 PID: 6079 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 0 UID: 0 PID: 6079 Comm: syz.3.270 Not tainted 6.12.0-rc1-syzkaller-00046-g7ec462100ef9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Code: ff 89 de e8 78 1c fe fc 84 db 0f 85 66 ff ff ff e8 8b 1a fe fc c6 05 e0 7e b8 0b 01 90 48 c7 c7 40 4a d1 8b e8 17 03 bf fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 68 1a fe fc 0f b6 1d bb 7e b8 0b 31 RSP: 0018:ffffc9001592f920 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90009b29000 RDX: 0000000000040000 RSI: ffffffff814e7336 RDI: 0000000000000001 RBP: ffff8880276454a4 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffff8880276454a4 R15: 0000000000000001 FS: 00007fa98f8416c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556522f808 CR3: 0000000079518000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:275 [inline] __refcount_dec_and_test include/linux/refcount.h:307 [inline] refcount_dec_and_test include/linux/refcount.h:325 [inline] skb_unref include/linux/skbuff.h:1232 [inline] __sk_skb_reason_drop net/core/skbuff.c:1213 [inline] sk_skb_reason_drop+0x183/0x1a0 net/core/skbuff.c:1241 kfree_skb_reason include/linux/skbuff.h:1262 [inline] kfree_skb include/linux/skbuff.h:1271 [inline] j1939_session_destroy+0x163/0x460 net/can/j1939/transport.c:282 __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put+0x64/0x90 net/can/j1939/transport.c:299 j1939_sk_send_loop net/can/j1939/socket.c:1202 [inline] j1939_sk_sendmsg+0xf12/0x1370 net/can/j1939/socket.c:1277 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2602 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2656 __sys_sendmsg+0x117/0x1f0 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa98e97dff9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa98f841038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa98eb35f80 RCX: 00007fa98e97dff9 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000006 RBP: 00007fa98e9f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa98eb35f80 R15: 00007ffcf7e34d18