================================================================== BUG: KASAN: use-after-free in do_shrink_slab+0xbe6/0xce0 mm/vmscan.c:785 Read of size 8 at addr ffff88806def95b8 by task syz-executor.1/12052 CPU: 3 PID: 12052 Comm: syz-executor.1 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 shrink_zones mm/vmscan.c:6343 [inline] do_try_to_free_pages+0x3b4/0x17a0 mm/vmscan.c:6405 try_to_free_pages+0x2e1/0x960 mm/vmscan.c:6640 __perform_reclaim mm/page_alloc.c:4754 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4776 [inline] __alloc_pages_slowpath.constprop.0+0x8b6/0x23d0 mm/page_alloc.c:5182 __alloc_pages+0x4a6/0x5a0 mm/page_alloc.c:5567 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2280 folio_alloc+0x1c/0x70 mm/mempolicy.c:2290 filemap_alloc_folio+0x306/0x3a0 mm/filemap.c:971 __filemap_get_folio+0x328/0xd90 mm/filemap.c:1965 pagecache_get_page+0x2e/0x280 mm/folio-compat.c:110 ext4_da_write_begin+0x41d/0xb50 fs/ext4/inode.c:2995 generic_perform_write+0x252/0x570 mm/filemap.c:3753 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:285 ext4_file_write_iter+0x8b8/0x16e0 fs/ext4/file.c:700 __kernel_write_iter+0x25e/0x730 fs/read_write.c:517 dump_emit_page fs/coredump.c:857 [inline] dump_user_range+0x230/0x700 fs/coredump.c:908 elf_core_dump+0x26de/0x3510 fs/binfmt_elf.c:2311 do_coredump+0x26c5/0x3bc0 fs/coredump.c:755 get_signal+0x1be1/0x2430 kernel/signal.c:2844 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:309 asm_exc_general_protection+0x22/0x30 arch/x86/include/asm/idtentry.h:564 RIP: 0033:0x7f793d08b5b1 Code: 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 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:00000000200000a0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f793d1abf80 RCX: 00007f793d08b5a9 RDX: 00000000200000c0 RSI: 00000000200000a0 RDI: 0000000000000000 RBP: 00007f793d0e6580 R08: 0000000020000140 R09: 0000000020000140 R10: 0000000020000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffda1896ef R14: 00007f793e1b1300 R15: 0000000000022000 Allocated by task 12054: 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_clone3+0x1cd/0x2e0 kernel/fork.c:2970 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 12054: 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_clone3+0x1cd/0x2e0 kernel/fork.c:2970 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 ffff88806def9000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1464 bytes inside of 2048-byte region [ffff88806def9000, ffff88806def9800) The buggy address belongs to the physical page: page:ffffea0001b7be40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6def9 flags: 0x4fff00000000200(slab|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000000200 ffffea0001e69888 ffffea0001b9e448 ffff888011840800 raw: 0000000000000000 ffff88806def9000 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 0x40cc0(GFP_KERNEL|__GFP_COMP), pid 12054, tgid 12050 (syz-executor.1), ts 415299006374, free_ts 415169607196 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 fallback_alloc+0x1e2/0x2d0 mm/slab.c:3113 __do_cache_alloc mm/slab.c:3217 [inline] slab_alloc_node mm/slab.c:3250 [inline] __kmem_cache_alloc_node+0x16c/0x500 mm/slab.c:3549 __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] 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_clone3+0x1cd/0x2e0 kernel/fork.c:2970 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 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 __folio_put_small mm/swap.c:105 [inline] __folio_put+0xc1/0x130 mm/swap.c:128 folio_put include/linux/mm.h:1159 [inline] put_page include/linux/mm.h:1211 [inline] free_page_and_swap_cache+0x253/0x2c0 mm/swap_state.c:299 __tlb_remove_table arch/x86/include/asm/tlb.h:34 [inline] __tlb_remove_table_free mm/mmu_gather.c:115 [inline] tlb_remove_table_rcu+0x85/0xe0 mm/mmu_gather.c:170 rcu_do_batch kernel/rcu/tree.c:2248 [inline] rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2508 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571 Memory state around the buggy address: ffff88806def9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806def9500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806def9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806def9600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806def9680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================