================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3c7b/0x56e0 kernel/locking/lockdep.c:4250 Read of size 8 at addr ffff8880a30b12c8 by task syz-executor.1/29002 CPU: 1 PID: 29002 Comm: syz-executor.1 Not tainted 5.8.0-rc5-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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 __lock_acquire+0x3c7b/0x56e0 kernel/locking/lockdep.c:4250 lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:4959 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:159 prepare_to_wait_event+0x5b/0x650 kernel/sched/wait.c:280 iw_cm_disconnect+0x295/0x320 drivers/infiniband/core/iwcm.c:316 rdma_disconnect+0x12a/0xab0 drivers/infiniband/core/cma.c:4307 p9_cm_event_handler+0x17c/0x2f0 net/9p/trans_rdma.c:280 cma_cm_event_handler+0xa9/0x610 drivers/infiniband/core/cma.c:1929 cma_remove_id_dev drivers/infiniband/core/cma.c:4811 [inline] cma_process_remove drivers/infiniband/core/cma.c:4832 [inline] cma_remove_one+0x782/0xbf0 drivers/infiniband/core/cma.c:4855 remove_client_context+0xbe/0x110 drivers/infiniband/core/device.c:736 disable_device+0x13b/0x270 drivers/infiniband/core/device.c:1282 __ib_unregister_device+0x91/0x190 drivers/infiniband/core/device.c:1450 ib_unregister_device_and_put+0x57/0x80 drivers/infiniband/core/device.c:1514 nldev_dellink+0x209/0x310 drivers/infiniband/core/nldev.c:1571 rdma_nl_rcv_msg+0x34a/0x5b0 drivers/infiniband/core/netlink.c:195 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x31a/0x470 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2352 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1d9 Code: Bad RIP value. RSP: 002b:00007fc297ab7c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000029840 RCX: 000000000045c1d9 RDX: 0000000000000000 RSI: 0000000020002b40 RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffc28e3de2f R14: 00007fc297ab89c0 R15: 000000000078bf0c Allocated by task 28994: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 kmem_cache_alloc_trace+0x14f/0x2d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] iw_create_cm_id+0x52/0x3a0 drivers/infiniband/core/iwcm.c:248 cma_connect_iw drivers/infiniband/core/cma.c:3996 [inline] rdma_connect+0x46f/0x1ec0 drivers/infiniband/core/cma.c:4052 rdma_create_trans+0xefc/0x13e0 net/9p/trans_rdma.c:722 p9_client_create+0x81a/0x10c0 net/9p/client.c:1039 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:406 v9fs_mount+0x79/0x970 fs/9p/vfs_super.c:124 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] do_mount+0x1592/0x1fe0 fs/namespace.c:3200 __do_sys_mount fs/namespace.c:3410 [inline] __se_sys_mount fs/namespace.c:3387 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 28994: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 free_cm_id drivers/infiniband/core/iwcm.c:205 [inline] iwcm_deref_id+0xd4/0x120 drivers/infiniband/core/iwcm.c:217 destroy_cm_id+0x266/0x520 drivers/infiniband/core/iwcm.c:444 cma_connect_iw drivers/infiniband/core/cma.c:4026 [inline] rdma_connect+0xf22/0x1ec0 drivers/infiniband/core/cma.c:4052 rdma_create_trans+0xefc/0x13e0 net/9p/trans_rdma.c:722 p9_client_create+0x81a/0x10c0 net/9p/client.c:1039 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:406 v9fs_mount+0x79/0x970 fs/9p/vfs_super.c:124 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] do_mount+0x1592/0x1fe0 fs/namespace.c:3200 __do_sys_mount fs/namespace.c:3410 [inline] __se_sys_mount fs/namespace.c:3387 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880a30b1000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 712 bytes inside of 1024-byte region [ffff8880a30b1000, ffff8880a30b1400) The buggy address belongs to the page: page:ffffea00028c2c40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00027a5408 ffffea00029a1f08 ffff8880aa000c40 raw: 0000000000000000 ffff8880a30b1000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a30b1180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a30b1200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a30b1280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a30b1300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a30b1380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================