================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0x2dd6/0x3b30 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff888041f7ec18 by task swapper/3/0 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.9.0-rc1-syzkaller-00061-g8d025e2092e2 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 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+0x2dd6/0x3b30 kernel/locking/lockdep.c:5005 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __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:394 [inline] p9_req_put net/9p/client.c:402 [inline] p9_req_put+0xca/0x250 net/9p/client.c:399 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:161 [inline] handle_irq arch/x86/kernel/irq.c:238 [inline] __common_interrupt+0xde/0x250 arch/x86/kernel/irq.c:257 common_interrupt+0xab/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:default_idle+0xf/0x20 arch/x86/kernel/process.c:743 Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 d9 48 00 fb f4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffffc90000197e08 EFLAGS: 00000246 RAX: 000000000014ad4b RBX: 0000000000000003 RCX: ffffffff8addc6a9 RDX: 0000000000000000 RSI: ffffffff8b2cc840 RDI: ffffffff8b8f4760 RBP: ffffed1002fd7000 R08: 0000000000000001 R09: ffffed100d666fdd R10: ffff88806b337eeb R11: 0000000000000000 R12: 0000000000000003 R13: ffff888017eb8000 R14: ffffffff8fe11a10 R15: 0000000000000000 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x32c/0x3f0 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x148 Allocated by task 19842: 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:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc include/linux/slab.h:628 [inline] p9_client_create+0xcf/0x1210 net/9p/client.c:980 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa90 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1797 do_new_mount fs/namespace.c:3352 [inline] path_mount+0x14e6/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount fs/namespace.c:3875 [inline] __x64_sys_mount+0x297/0x320 fs/namespace.c:3875 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Freed by task 19842: 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:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x129/0x390 mm/slub.c:4390 p9_client_create+0xaaa/0x1210 net/9p/client.c:1051 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xa90 fs/9p/vfs_super.c:122 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x8f/0x380 fs/super.c:1797 do_new_mount fs/namespace.c:3352 [inline] path_mount+0x14e6/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount fs/namespace.c:3875 [inline] __x64_sys_mount+0x297/0x320 fs/namespace.c:3875 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 The buggy address belongs to the object at ffff888041f7ec00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff888041f7ec00, ffff888041f7ee00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x41f7c head: order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000840 ffff888015442c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 head: 00fff80000000840 ffff888015442c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 head: 00fff80000000002 ffffea000107df01 dead000000000122 00000000ffffffff head: 0000000400000000 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 18441, tgid 18441 (syz-executor.1), ts 257542693381, free_ts 256944930736 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534 prep_new_page mm/page_alloc.c:1541 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2391 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610 __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] __do_kmalloc_node mm/slub.c:3965 [inline] __kmalloc+0x3b4/0x440 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] kzalloc include/linux/slab.h:749 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x337/0x1940 net/ipv6/route.c:3759 ip6_route_add+0x26/0x190 net/ipv6/route.c:3851 addrconf_add_mroute+0x1de/0x350 net/ipv6/addrconf.c:2547 addrconf_add_dev+0x14e/0x1c0 net/ipv6/addrconf.c:2565 inet6_addr_add+0x1a8/0xbe0 net/ipv6/addrconf.c:3021 inet6_rtm_newaddr+0x11e7/0x1ab0 net/ipv6/addrconf.c:5045 rtnetlink_rcv_msg+0x3c7/0xe60 net/core/rtnetlink.c:6595 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2559 page last free pid 4910 tgid 4910 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487 __folio_put_large+0x10d/0x1c0 mm/swap.c:132 __folio_put+0x1c0/0x1f0 mm/swap.c:140 skb_kfree_head net/core/skbuff.c:1096 [inline] skb_free_head+0x110/0x1e0 net/core/skbuff.c:1108 skb_release_data+0x76c/0x990 net/core/skbuff.c:1136 skb_release_all net/core/skbuff.c:1202 [inline] __kfree_skb net/core/skbuff.c:1216 [inline] consume_skb net/core/skbuff.c:1432 [inline] consume_skb+0xd2/0x170 net/core/skbuff.c:1426 __unix_dgram_recvmsg+0x8cd/0x1000 net/unix/af_unix.c:2514 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2531 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x1f6/0x250 net/socket.c:1068 sock_read_iter+0x2c7/0x3c0 net/socket.c:1138 call_read_iter include/linux/fs.h:2102 [inline] do_iter_readv_writev+0x5e6/0x780 fs/read_write.c:739 vfs_readv+0x33e/0x870 fs/read_write.c:932 do_readv+0x287/0x370 fs/read_write.c:994 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Memory state around the buggy address: ffff888041f7eb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888041f7eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888041f7ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888041f7ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888041f7ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 4c 01 c7 add %r8,%rdi 3: 4c 29 c2 sub %r8,%rdx 6: e9 72 ff ff ff jmp 0xffffff7d b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: 66 90 xchg %ax,%ax 21: 0f 00 2d 83 d9 48 00 verw 0x48d983(%rip) # 0x48d9ab 28: fb sti 29: f4 hlt * 2a: fa cli <-- trapping instruction 2b: c3 ret 2c: cc int3 2d: cc int3 2e: cc int3 2f: cc int3 30: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1) 37: 00 00 00 00 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop