================================================================== BUG: KASAN: use-after-free in do_shrink_slab+0xb15/0xbd0 mm/vmscan.c:774 Read of size 8 at addr ffff88805a16e5b8 by task syz-fuzzer/3814 CPU: 3 PID: 3814 Comm: syz-fuzzer Not tainted 6.0.0-syzkaller-06475-g4c86114194e6 #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:317 [inline] print_report.cold+0x2ba/0x6e9 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 shrink_node_memcgs mm/vmscan.c:3182 [inline] shrink_node+0x8c9/0x1e80 mm/vmscan.c:3304 shrink_zones mm/vmscan.c:3542 [inline] do_try_to_free_pages+0x3b4/0x17a0 mm/vmscan.c:3601 try_to_free_pages+0x2a7/0x840 mm/vmscan.c:3836 __perform_reclaim mm/page_alloc.c:4750 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4772 [inline] __alloc_pages_slowpath.constprop.0+0x88a/0x2300 mm/page_alloc.c:5177 __alloc_pages+0x43d/0x510 mm/page_alloc.c:5562 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 folio_alloc+0x1c/0x70 mm/mempolicy.c:2280 filemap_alloc_folio+0x306/0x3a0 mm/filemap.c:970 page_cache_ra_unbounded+0x1af/0x550 mm/readahead.c:242 do_page_cache_ra mm/readahead.c:293 [inline] page_cache_ra_order+0x67a/0x980 mm/readahead.c:550 do_sync_mmap_readahead mm/filemap.c:3028 [inline] filemap_fault+0x1641/0x2610 mm/filemap.c:3120 __do_fault+0x10d/0x610 mm/memory.c:4173 do_read_fault mm/memory.c:4524 [inline] do_fault mm/memory.c:4653 [inline] handle_pte_fault mm/memory.c:4917 [inline] __handle_mm_fault+0x2130/0x39b0 mm/memory.c:5059 handle_mm_fault+0x1c8/0x780 mm/memory.c:5157 do_user_addr_fault+0x475/0x1210 arch/x86/mm/fault.c:1407 handle_page_fault arch/x86/mm/fault.c:1498 [inline] exc_page_fault+0x94/0x170 arch/x86/mm/fault.c:1554 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x4b9485 Code: 0e 00 00 00 48 8d 1c 06 48 8b 0d 96 0b d1 00 48 89 d0 48 8b 2c 24 48 83 c4 08 c3 48 c1 e6 1e 48 63 c3 48 09 f0 48 0f ba e8 3f <48> 8b 15 74 0b d1 00 48 89 cb 48 89 d1 48 8b 2c 24 48 83 c4 08 c3 RSP: 002b:000000c000be1c30 EFLAGS: 00010206 RAX: c0c83a9de8952518 RBX: 0000000028952518 RCX: 0000002a6abecb8a RDX: 0000000000000000 RSI: 40c83a9dc0000000 RDI: 0000000000000001 RBP: 000000c000be1c30 R08: 00000000000000ed R09: 00007ffdcd36d080 R10: 00007ffdcd36d090 R11: 000000000000b16a R12: 000000c000be1be8 R13: 0000000000c02b60 R14: 000000c0000831e0 R15: 00007f884cdb9f83 Allocated by task 3868: 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+0xa6/0xd0 mm/kasan/common.c:525 kasan_kmalloc include/linux/kasan.h:234 [inline] __do_kmalloc mm/slab.c:3686 [inline] __kmalloc+0x1f9/0x4a0 mm/slab.c:3695 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+0x304d/0x7090 kernel/fork.c:2257 kernel_clone+0xe7/0xab0 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2805 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 3868: 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+0x13d/0x1a0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3418 [inline] kfree+0x173/0x390 mm/slab.c:3786 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+0x304d/0x7090 kernel/fork.c:2257 kernel_clone+0xe7/0xab0 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2805 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 ffff88805a16e000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1464 bytes inside of 2048-byte region [ffff88805a16e000, ffff88805a16e800) The buggy address belongs to the physical page: page:ffffea0001685b80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a16e flags: 0x4fff00000000200(slab|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000000200 ffffea00015aa2c8 ffffea0001681048 ffff888011840800 raw: 0000000000000000 ffff88805a16e000 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 0xc2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC), pid 3772, tgid 3772 (kworker/2:4), ts 224266943146, free_ts 222919095347 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages_slowpath.constprop.0+0x34d/0x2300 mm/page_alloc.c:5084 __alloc_pages+0x43d/0x510 mm/page_alloc.c:5562 __alloc_pages_node include/linux/gfp.h:243 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2569 fallback_alloc+0x1e2/0x2d0 mm/slab.c:3112 slab_alloc_node mm/slab.c:3225 [inline] kmem_cache_alloc_node_trace+0x176/0x570 mm/slab.c:3601 __do_kmalloc_node mm/slab.c:3623 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3638 kmalloc_reserve net/core/skbuff.c:437 [inline] __alloc_skb+0xd9/0x2f0 net/core/skbuff.c:509 alloc_skb include/linux/skbuff.h:1265 [inline] alloc_skb_with_frags+0x93/0x6c0 net/core/skbuff.c:6124 sock_alloc_send_pskb+0x7a3/0x930 net/core/sock.c:2719 sock_alloc_send_skb include/net/sock.h:1884 [inline] mld_newpack.isra.0+0x1b9/0x770 net/ipv6/mcast.c:1748 add_grhead+0x295/0x340 net/ipv6/mcast.c:1851 add_grec+0x1082/0x1560 net/ipv6/mcast.c:1989 mld_send_cr net/ipv6/mcast.c:2115 [inline] mld_ifc_work+0x452/0xdc0 net/ipv6/mcast.c:2653 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 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 slab_destroy mm/slab.c:1615 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1635 __cache_free_alien mm/slab.c:774 [inline] cache_free_alien mm/slab.c:790 [inline] ___cache_free+0x200/0x3d0 mm/slab.c:3445 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x97/0xb0 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 mm/slab.c:3294 [inline] kmem_cache_alloc_trace+0x212/0x460 mm/slab.c:3557 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] fib6_info_alloc+0xc1/0x210 net/ipv6/ip6_fib.c:156 ip6_route_info_create+0x341/0x18f0 net/ipv6/route.c:3749 ip6_route_add+0x24/0x150 net/ipv6/route.c:3843 addrconf_add_mroute+0x1e1/0x310 net/ipv6/addrconf.c:2489 addrconf_add_dev+0x156/0x1c0 net/ipv6/addrconf.c:2507 addrconf_dev_config+0x1ec/0x410 net/ipv6/addrconf.c:3382 addrconf_notify+0xf36/0x1c10 net/ipv6/addrconf.c:3635 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 Memory state around the buggy address: ffff88805a16e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a16e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a16e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a16e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a16e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================