================================================================== BUG: KASAN: use-after-free in do_shrink_slab+0xb15/0xbd0 mm/vmscan.c:774 Read of size 8 at addr ffff88804185c5b8 by task syz-executor.3/13630 CPU: 1 PID: 13630 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 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:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 do_shrink_slab+0xb15/0xbd0 mm/vmscan.c:774 shrink_slab+0x17c/0x6f0 mm/vmscan.c:991 drop_slab_node mm/vmscan.c:1026 [inline] drop_slab+0x104/0x280 mm/vmscan.c:1036 drop_caches_sysctl_handler+0xf6/0x110 fs/drop_caches.c:66 proc_sys_call_handler+0x49c/0x6d0 fs/proc/proc_sysctl.c:611 call_write_iter include/linux/fs.h:2190 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x70/0xa0 fs/read_write.c:902 iter_file_splice_write+0x741/0xc90 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:931 splice_direct_to_actor+0x331/0x8a0 fs/splice.c:886 do_splice_direct+0x1a7/0x270 fs/splice.c:974 do_sendfile+0xb19/0x1270 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1309 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: 0033:0x7fce5fa8b5a9 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:00007fce60beb168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fce5fbac050 RCX: 00007fce5fa8b5a9 RDX: 0000000020002080 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 00007fce5fae6580 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000870 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fce600dfb1f R14: 00007fce60beb300 R15: 0000000000022000 Allocated by task 13598: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc include/linux/slab.h:605 [inline] kzalloc include/linux/slab.h:733 [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+0x307b/0x7110 kernel/fork.c:2257 kernel_clone+0xe7/0x8f0 kernel/fork.c:2672 __do_sys_clone+0xba/0x100 kernel/fork.c:2806 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 13598: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1759 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1785 slab_free mm/slub.c:3539 [inline] kfree+0xe2/0x580 mm/slub.c:4567 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+0x307b/0x7110 kernel/fork.c:2257 kernel_clone+0xe7/0x8f0 kernel/fork.c:2672 __do_sys_clone+0xba/0x100 kernel/fork.c:2806 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:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1200 kernel/workqueue.c:1517 queue_work_on+0xee/0x110 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:503 [inline] afs_queue_server_manager fs/afs/server.c:612 [inline] afs_purge_servers+0xea/0x340 fs/afs/server.c:626 afs_net_exit+0x16d/0x320 fs/afs/main.c:157 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1200 kernel/workqueue.c:1517 queue_work_on+0xee/0x110 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:503 [inline] afs_queue_cell_manager+0x64/0xe0 fs/afs/cell.c:520 afs_cell_purge+0x105/0x2b0 fs/afs/cell.c:946 afs_net_exit+0x165/0x320 fs/afs/main.c:156 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff88804185c000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1464 bytes inside of 2048-byte region [ffff88804185c000, ffff88804185c800) The buggy address belongs to the physical page: page:ffffea0001061600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x41858 head:ffffea0001061600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 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 12729, tgid 12728 (syz-executor.5), ts 779960123599, free_ts 779950169057 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x84f/0xe80 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] kmem_cache_alloc_trace+0x323/0x3e0 mm/slub.c:3287 kmalloc include/linux/slab.h:600 [inline] rtnl_newlink+0x46/0xa0 net/core/rtnetlink.c:3590 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6091 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2540 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2553 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+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] slab_alloc mm/slub.c:3256 [inline] __kmalloc+0x28a/0x340 mm/slub.c:4425 kmalloc include/linux/slab.h:605 [inline] tomoyo_realpath_from_path+0xbf/0x600 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:320 [inline] tomoyo_file_open+0x9d/0xc0 security/tomoyo/tomoyo.c:315 security_file_open+0x45/0xb0 security/security.c:1648 do_dentry_open+0x575/0x13f0 fs/open.c:869 do_open fs/namei.c:3557 [inline] path_openat+0x1c92/0x28f0 fs/namei.c:3691 do_filp_open+0x1b6/0x400 fs/namei.c:3718 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1337 Memory state around the buggy address: ffff88804185c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804185c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804185c580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804185c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804185c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================