================================================================== BUG: KASAN: slab-use-after-free in afs_dynroot_readdir_cells fs/afs/dynroot.c:297 [inline] BUG: KASAN: slab-use-after-free in afs_dynroot_readdir+0x94e/0xb70 fs/afs/dynroot.c:353 Read of size 4 at addr ffff888033a63148 by task syz.0.2634/11813 CPU: 1 UID: 0 PID: 11813 Comm: syz.0.2634 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 afs_dynroot_readdir_cells fs/afs/dynroot.c:297 [inline] afs_dynroot_readdir+0x94e/0xb70 fs/afs/dynroot.c:353 iterate_dir+0x296/0xaf0 fs/readdir.c:108 __do_sys_getdents fs/readdir.c:326 [inline] __se_sys_getdents fs/readdir.c:312 [inline] __x64_sys_getdents+0x13c/0x2b0 fs/readdir.c:312 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f007cb8f7c9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f007da6a038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f007cde5fa0 RCX: 00007f007cb8f7c9 RDX: 00000000000000b8 RSI: 0000200000001fc0 RDI: 0000000000000003 RBP: 00007f007cc13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f007cde6038 R14: 00007f007cde5fa0 R15: 00007fffa843be78 Allocated by task 11807: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] afs_alloc_cell fs/afs/cell.c:137 [inline] afs_lookup_cell+0x8b2/0x1900 fs/afs/cell.c:278 afs_dynroot_lookup_cell fs/afs/dynroot.c:111 [inline] afs_dynroot_lookup+0x2e2/0xa90 fs/afs/dynroot.c:160 __lookup_slow+0x251/0x460 fs/namei.c:1858 lookup_slow+0x50/0x70 fs/namei.c:1875 walk_component fs/namei.c:2221 [inline] lookup_last fs/namei.c:2722 [inline] path_lookupat+0x5e9/0xc40 fs/namei.c:2746 filename_lookup+0x224/0x5f0 fs/namei.c:2775 user_path_at+0x3a/0x60 fs/namei.c:3567 do_mount fs/namespace.c:4032 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x1fb/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 11813: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6876 afs_cell_destroy+0x21c/0x310 fs/afs/cell.c:582 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x15f0 kernel/rcu/tree.c:2857 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556 __call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3119 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Second to last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556 insert_work+0x36/0x230 kernel/workqueue.c:2180 __queue_work+0x94f/0x10e0 kernel/workqueue.c:2335 queue_work_on+0x1a4/0x1f0 kernel/workqueue.c:2386 queue_work include/linux/workqueue.h:669 [inline] afs_put_cell.part.0+0x1ab/0x240 fs/afs/cell.c:627 afs_put_cell fs/afs/cell.c:615 [inline] afs_manage_cell_work+0x6ac/0x1960 fs/afs/cell.c:887 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff888033a63000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 328 bytes inside of freed 1024-byte region [ffff888033a63000, ffff888033a63400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33a60 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b442dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000ce9801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5656, tgid 5656 (dhcpcd-run-hook), ts 38831842937, free_ts 38807844702 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x4fc/0x910 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] tomoyo_init_log+0x1385/0x2140 security/tomoyo/audit.c:275 tomoyo_supervisor+0x302/0x13b0 security/tomoyo/common.c:2198 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x191/0x200 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0xec1/0x20b0 security/tomoyo/domain.c:888 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline] tomoyo_bprm_check_security+0x12d/0x1d0 security/tomoyo/tomoyo.c:92 security_bprm_check+0x1b9/0x1e0 security/security.c:794 search_binary_handler fs/exec.c:1659 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve fs/exec.c:1753 [inline] bprm_execve+0x81e/0x1620 fs/exec.c:1729 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1859 page last free pid 5655 tgid 5655 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270 vm_area_alloc+0x1f/0x160 mm/vma_init.c:32 __install_special_mapping mm/mmap.c:1446 [inline] _install_special_mapping+0x2e/0x3d0 mm/mmap.c:1496 map_vdso+0x16e/0x580 arch/x86/entry/vdso/vma.c:159 arch_setup_additional_pages+0x41/0x60 arch/x86/entry/vdso/vma.c:242 load_elf_binary+0x1e51/0x4fe0 fs/binfmt_elf.c:1291 search_binary_handler fs/exec.c:1669 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve fs/exec.c:1753 [inline] bprm_execve+0x8c2/0x1620 fs/exec.c:1729 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1859 do_execve fs/exec.c:1933 [inline] __do_sys_execve fs/exec.c:2009 [inline] __se_sys_execve fs/exec.c:2004 [inline] __x64_sys_execve+0x8e/0xb0 fs/exec.c:2004 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888033a63000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888033a63080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888033a63100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888033a63180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888033a63200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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