================================================================== BUG: KASAN: use-after-free in do_shrink_slab+0xbe6/0xce0 mm/vmscan.c:785 Read of size 8 at addr ffff888067c935b8 by task syz-executor.2/29015 CPU: 3 PID: 29015 Comm: syz-executor.2 Not tainted 6.1.0-rc1-syzkaller-00002-gbbb8ceb5e242 #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 exc_page_fault+0xbc/0x170 arch/x86/mm/fault.c:1578 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7f2aeb827d77 Code: 38 5d 41 5c c3 48 8d 3d 75 d6 0b 00 e8 c2 f7 ff ff 48 8d 3d 77 d6 0b 00 e8 b6 f7 ff ff 66 0f 1f 44 00 00 55 89 fd 48 83 ec 10 <64> 8b 04 25 b4 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8 RSP: 002b:00007f2aec9fe1a0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 00007f2aeb9ac120 RCX: 00007f2aeb88b5a9 RDX: 00007f2aec9fe1c0 RSI: 00007f2aec9fe2f0 RDI: 000000000000000b RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000058 R10: 00007f2aeca1d050 R11: 0000000000000246 R12: 0000000000000058 R13: 00007ffe7b49680f R14: 00007f2aeca1d300 R15: 0000000000022000 Allocated by task 29030: 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 29030: 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 ffff888067c93000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1464 bytes inside of 2048-byte region [ffff888067c93000, ffff888067c93800) The buggy address belongs to the physical page: page:ffffea00019f24c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x67c93 flags: 0x4fff00000000200(slab|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000000200 ffffea0001a37308 ffffea000178bc08 ffff888011840800 raw: 0000000000000000 ffff888067c93000 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 29030, tgid 29021 (syz-executor.2), ts 1047115223922, free_ts 1047035616990 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 __vunmap+0x85d/0xd30 mm/vmalloc.c:2713 free_work+0x58/0x70 mm/vmalloc.c:97 process_one_work+0x9bf/0x1710 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 Memory state around the buggy address: ffff888067c93480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888067c93500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888067c93580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888067c93600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888067c93680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================