================================================================== BUG: KASAN: use-after-free in do_shrink_slab+0xbe6/0xce0 mm/vmscan.c:785 Read of size 8 at addr ffff88801b9c65b8 by task kswapd1/128 CPU: 2 PID: 128 Comm: kswapd1 Not tainted 6.1.0-rc1-syzkaller-00025-gaae703b02f92 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 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/0x461 mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 do_shrink_slab+0xbe6/0xce0 mm/vmscan.c:785 shrink_slab+0x175/0x660 mm/vmscan.c:1002 shrink_node_memcgs mm/vmscan.c:6076 [inline] shrink_node+0x93d/0x1f30 mm/vmscan.c:6105 kswapd_shrink_node mm/vmscan.c:6894 [inline] balance_pgdat+0x8f5/0x1530 mm/vmscan.c:7084 kswapd+0x707/0xfc0 mm/vmscan.c:7344 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Allocated by task 19435: 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+0x9f/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 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x306e/0x7190 kernel/fork.c:2256 kernel_clone+0xe7/0x980 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2812 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 19435: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] __cache_free mm/slab.c:3389 [inline] __do_kmem_cache_free mm/slab.c:3585 [inline] __kmem_cache_free+0xc9/0x3a0 mm/slab.c:3592 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 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x306e/0x7190 kernel/fork.c:2256 kernel_clone+0xe7/0x980 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2812 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 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0x7b/0x90 mm/kasan/generic.c:481 call_rcu+0x99/0x820 kernel/rcu/tree.c:2796 netlink_release+0xeff/0x1db0 net/netlink/af_netlink.c:815 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x18/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16b/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:296 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88801b9c6000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1464 bytes inside of 2048-byte region [ffff88801b9c6000, ffff88801b9c6800) The buggy address belongs to the physical page: page:ffffea00006e7180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b9c6 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea000093c0c8 ffffea00009a7348 ffff888011840800 raw: 0000000000000000 ffff88801b9c6000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2c20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_THISNODE), pid 18289, tgid 18280 (syz-executor.2), ts 1139413243038, free_ts 1138762909712 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4287 __alloc_pages_slowpath.constprop.0+0x36b/0x23d0 mm/page_alloc.c:5088 __alloc_pages+0x4a6/0x5a0 mm/page_alloc.c:5567 __alloc_pages_node include/linux/gfp.h:223 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2570 cache_alloc_refill+0x27f/0x380 mm/slab.c:2943 ____cache_alloc mm/slab.c:3019 [inline] ____cache_alloc mm/slab.c:3002 [inline] __do_cache_alloc mm/slab.c:3202 [inline] slab_alloc_node mm/slab.c:3250 [inline] __kmem_cache_alloc_node+0x442/0x500 mm/slab.c:3549 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc_node_track_caller+0x45/0xc0 mm/slab_common.c:975 kmalloc_reserve net/core/skbuff.c:437 [inline] __alloc_skb+0xd9/0x2f0 net/core/skbuff.c:509 alloc_skb include/linux/skbuff.h:1267 [inline] nlmsg_new include/net/netlink.h:964 [inline] audit_buffer_alloc kernel/audit.c:1780 [inline] audit_log_start.part.0+0x27f/0x740 kernel/audit.c:1898 audit_log_start+0x5f/0x90 kernel/audit.c:1854 audit_seccomp+0x5d/0x290 kernel/auditsc.c:2990 seccomp_log kernel/seccomp.c:994 [inline] __seccomp_filter+0x8fc/0x1080 kernel/seccomp.c:1312 __secure_computing+0x246/0x3e0 kernel/seccomp.c:1342 syscall_trace_enter.constprop.0+0x90/0x250 kernel/entry/common.c:72 do_syscall_64+0x16/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x63/0xcd 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 slab_destroy mm/slab.c:1615 [inline] slabs_destroy+0x85/0xc0 mm/slab.c:1635 cache_flusharray mm/slab.c:3360 [inline] ___cache_free+0x2a8/0x3d0 mm/slab.c:3423 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4f/0x1a0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x5f/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/slab.c:3257 [inline] slab_alloc mm/slab.c:3265 [inline] __kmem_cache_alloc_lru mm/slab.c:3442 [inline] kmem_cache_alloc+0x218/0x450 mm/slab.c:3461 kmem_cache_zalloc include/linux/slab.h:702 [inline] alloc_buffer_head+0x20/0x140 fs/buffer.c:2899 alloc_page_buffers+0x280/0x790 fs/buffer.c:829 grow_dev_page fs/buffer.c:965 [inline] grow_buffers fs/buffer.c:1011 [inline] __getblk_slow+0x505/0x1030 fs/buffer.c:1038 __getblk_gfp+0x6e/0x80 fs/buffer.c:1333 sb_getblk include/linux/buffer_head.h:356 [inline] ext4_getblk+0x20d/0x7a0 fs/ext4/inode.c:868 ext4_bread_batch+0x7e/0x4f0 fs/ext4/inode.c:935 __ext4_find_entry+0x451/0x1030 fs/ext4/namei.c:1651 ext4_lookup_entry fs/ext4/namei.c:1752 [inline] ext4_lookup fs/ext4/namei.c:1820 [inline] ext4_lookup+0x4fc/0x700 fs/ext4/namei.c:1811 Memory state around the buggy address: ffff88801b9c6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b9c6500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801b9c6580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b9c6600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b9c6680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================