================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2dfe/0x3ce0 kernel/locking/lockdep.c:5065 Read of size 8 at addr ffff88804bd28818 by task syz.3.8/5439 CPU: 3 UID: 0 PID: 5439 Comm: syz.3.8 Not tainted 6.12.0-rc3-syzkaller-00454-gdb87114dcf13 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 __lock_acquire+0x2dfe/0x3ce0 kernel/locking/lockdep.c:5065 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 p9_tag_remove net/9p/client.c:397 [inline] p9_req_put net/9p/client.c:405 [inline] p9_req_put+0xaf/0x250 net/9p/client.c:402 req_done+0x1e7/0x2f0 net/9p/trans_virtio.c:147 vring_interrupt drivers/virtio/virtio_ring.c:2595 [inline] vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2570 __handle_irq_event_percpu+0x229/0x7c0 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x263/0xd10 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:247 [inline] call_irq_handler arch/x86/kernel/irq.c:259 [inline] __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:285 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 b6 b5 45 f6 48 89 df e8 ce 32 46 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 25 3a 37 f6 65 8b 05 d6 f0 de 74 85 c0 74 16 5b RSP: 0018:ffffc900037ef7f8 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff888032630f40 RCX: 1ffffffff2dce5b3 RDX: 0000000000000000 RSI: ffffffff8b6cd0c0 RDI: ffffffff8bd1aa80 RBP: 0000000000000282 R08: 0000000000000001 R09: fffffbfff2dc539f R10: ffffffff96e29cff R11: 0000000000000000 R12: 0000000000000002 R13: ffff888032630f80 R14: ffff888032630928 R15: ffff888032630da8 __unix_dgram_recvmsg+0x32a/0xe50 net/unix/af_unix.c:2462 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2537 sock_recvmsg_nosec net/socket.c:1051 [inline] ____sys_recvmsg+0x5f8/0x6b0 net/socket.c:2824 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2868 do_recvmmsg+0x2ba/0x750 net/socket.c:2962 __sys_recvmmsg net/socket.c:3041 [inline] __do_sys_recvmmsg net/socket.c:3064 [inline] __se_sys_recvmmsg net/socket.c:3057 [inline] __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3057 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: 0033:0x7f80daf7dff9 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:00007f80da9ff038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f80db136058 RCX: 00007f80daf7dff9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000005 RBP: 00007f80daff0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f80db136058 R15: 00007ffcb3d05758 Allocated by task 5440: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:878 [inline] p9_client_create+0xc8/0x11f0 net/9p/client.c:984 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1800 do_new_mount fs/namespace.c:3507 [inline] path_mount+0x14e6/0x1f20 fs/namespace.c:3834 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount fs/namespace.c:4032 [inline] __x64_sys_mount+0x294/0x320 fs/namespace.c:4032 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 Freed by task 5440: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x14f/0x4b0 mm/slub.c:4727 p9_client_create+0xa58/0x11f0 net/9p/client.c:1062 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1800 do_new_mount fs/namespace.c:3507 [inline] path_mount+0x14e6/0x1f20 fs/namespace.c:3834 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount fs/namespace.c:4032 [inline] __x64_sys_mount+0x294/0x320 fs/namespace.c:4032 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 The buggy address belongs to the object at ffff88804bd28800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff88804bd28800, ffff88804bd28a00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4bd28 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b042c80 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042c80 dead000000000122 0000000000000000 head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000002 ffffea00012f4a01 ffffffffffffffff 0000000000000000 head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5415, tgid 5411 (syz.2.3), ts 44009063788, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x101e/0x3070 mm/page_alloc.c:3457 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2412 [inline] allocate_slab mm/slub.c:2578 [inline] new_slab+0x2ba/0x3f0 mm/slub.c:2631 ___slab_alloc+0xdac/0x1880 mm/slub.c:3818 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] __kmalloc_cache_noprof+0x2b4/0x300 mm/slub.c:4290 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] create_io_worker+0xcc/0x5f0 io_uring/io-wq.c:832 create_worker_cb+0x200/0x260 io_uring/io-wq.c:355 task_work_run+0x14e/0x250 kernel/task_work.c:239 get_signal+0x1ca/0x2770 kernel/signal.c:2690 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f page_owner free stack trace missing Memory state around the buggy address: ffff88804bd28700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804bd28780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88804bd28800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804bd28880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804bd28900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: f5 cmc 1: 53 push %rbx 2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi 7: 48 89 fb mov %rdi,%rbx a: 48 83 c7 18 add $0x18,%rdi e: e8 b6 b5 45 f6 call 0xf645b5c9 13: 48 89 df mov %rbx,%rdi 16: e8 ce 32 46 f6 call 0xf64632e9 1b: f7 c5 00 02 00 00 test $0x200,%ebp 21: 75 23 jne 0x46 23: 9c pushf 24: 58 pop %rax 25: f6 c4 02 test $0x2,%ah 28: 75 37 jne 0x61 * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 25 3a 37 f6 call 0xf6373a59 34: 65 8b 05 d6 f0 de 74 mov %gs:0x74def0d6(%rip),%eax # 0x74def111 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx