================================================================== BUG: KASAN: use-after-free in __list_add_valid+0xa5/0xb0 lib/list_debug.c:30 Read of size 8 at addr ffff8880386db5c8 by task syz-executor.4/3323 CPU: 1 PID: 3323 Comm: syz-executor.4 Not tainted 6.1.0-rc1-syzkaller-00183-g225480f040b6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 __list_add_valid+0xa5/0xb0 lib/list_debug.c:30 __list_add include/linux/list.h:69 [inline] list_add_tail include/linux/list.h:102 [inline] register_shrinker_prepared mm/vmscan.c:695 [inline] __register_shrinker mm/vmscan.c:707 [inline] register_shrinker+0x6f/0x160 mm/vmscan.c:733 nfsd4_init_leases_net+0x390/0x490 fs/nfsd/nfs4state.c:4393 nfsd_init_net+0x1b5/0x430 fs/nfsd/nfsctl.c:1456 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f225ca8b5f9 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f225c1ff168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f225cbabf80 RCX: 00007f225ca8b5f9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f225cae67b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd8317cecf R14: 00007f225c1ff300 R15: 0000000000022000 Allocated by task 3313: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa1/0xb0 mm/kasan/common.c:380 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:955 [inline] __kmalloc+0x54/0xc0 mm/slab_common.c:968 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:712 [inline] ops_init+0xfb/0x470 net/core/net_namespace.c:124 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 3313: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2a/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xab/0x3b0 mm/slub.c:3674 ops_init+0xcd/0x470 net/core/net_namespace.c:139 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff8880386db000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1480 bytes inside of 2048-byte region [ffff8880386db000, ffff8880386db800) The buggy address belongs to the physical page: page:ffffea0000e1b600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x386d8 head:ffffea0000e1b600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888011842000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3313, tgid 3312 (syz-executor.1), ts 840678454257, free_ts 840624053174 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4287 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5554 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2280 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x191/0x3e0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc+0x44/0xc0 mm/slab_common.c:968 kmalloc include/linux/slab.h:581 [inline] sk_prot_alloc+0x143/0x290 net/core/sock.c:2030 sk_alloc+0x36/0x770 net/core/sock.c:2083 __netlink_create+0x63/0x380 net/netlink/af_netlink.c:647 __netlink_kernel_create+0x110/0x850 net/netlink/af_netlink.c:2045 netlink_kernel_create include/linux/netlink.h:62 [inline] nl_fib_lookup_init net/ipv4/fib_frontend.c:1403 [inline] fib_net_init net/ipv4/fib_frontend.c:1604 [inline] fib_net_init+0x217/0x3b0 net/ipv4/fib_frontend.c:1594 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1458 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1508 free_unref_page_prepare mm/page_alloc.c:3386 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3482 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x62/0x80 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] __kmem_cache_alloc_node+0x2da/0x3e0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc+0x44/0xc0 mm/slab_common.c:968 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:712 [inline] tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline] tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80 tomoyo_path_perm+0x368/0x400 security/tomoyo/file.c:831 tomoyo_path_symlink+0x94/0xe0 security/tomoyo/tomoyo.c:199 security_path_symlink+0xdf/0x150 security/security.c:1184 do_symlinkat+0x106/0x2e0 fs/namei.c:4424 __do_sys_symlinkat fs/namei.c:4446 [inline] __se_sys_symlinkat fs/namei.c:4443 [inline] __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4443 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880386db480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880386db500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880386db580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880386db600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880386db680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================