EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. fscrypt: AES-256-CBC-CTS using implementation "cts-cbc-aes-aesni" loop0: detected capacity change from 1024 to 767 ================================================================== BUG: KASAN: slab-use-after-free in ext4_search_dir+0xf1/0x1b0 fs/ext4/namei.c:1469 Read of size 1 at addr ffff88803fb8d62c by task syz.0.17/5473 CPU: 0 UID: 0 PID: 5473 Comm: syz.0.17 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_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 ext4_search_dir+0xf1/0x1b0 fs/ext4/namei.c:1469 ext4_find_inline_entry+0x492/0x5f0 fs/ext4/inline.c:1621 __ext4_find_entry+0x2fd/0x1f20 fs/ext4/namei.c:1542 ext4_lookup_entry fs/ext4/namei.c:1703 [inline] ext4_lookup+0x13d/0x6c0 fs/ext4/namei.c:1771 lookup_one_qstr_excl+0x12e/0x360 fs/namei.c:1705 filename_create+0x224/0x3c0 fs/namei.c:4227 do_mknodat+0x184/0x4d0 fs/namei.c:4359 __do_sys_mknod fs/namei.c:4405 [inline] __se_sys_mknod fs/namei.c:4403 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4403 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3a2bb8eec9 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:00007ffcb2ccbdd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f3a2bde5fa0 RCX: 00007f3a2bb8eec9 RDX: 0000000000000700 RSI: 0000000000000000 RDI: 0000200000000000 RBP: 00007f3a2bc11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3a2bde5fa0 R14: 00007f3a2bde5fa0 R15: 0000000000000003 Allocated by task 5273: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 mm_alloc+0x23/0xd0 kernel/fork.c:1113 bprm_mm_init fs/exec.c:261 [inline] alloc_bprm+0x398/0x5c0 fs/exec.c:1466 do_execveat_common+0x1b3/0x6a0 fs/exec.c:1811 do_execve fs/exec.c:1934 [inline] __do_sys_execve fs/exec.c:2010 [inline] __se_sys_execve fs/exec.c:2005 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2005 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5022: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4797 mmdrop include/linux/sched/mm.h:55 [inline] mmdrop_sched include/linux/sched/mm.h:83 [inline] mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline] finish_task_switch+0x3ee/0x950 kernel/sched/core.c:5218 context_switch kernel/sched/core.c:5328 [inline] __schedule+0x17a0/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 do_wait+0x294/0x510 kernel/exit.c:1711 kernel_wait4+0x1af/0x280 kernel/exit.c:1865 __do_sys_wait4 kernel/exit.c:1893 [inline] __se_sys_wait4 kernel/exit.c:1889 [inline] __x64_sys_wait4+0x133/0x1e0 kernel/exit.c:1889 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803fb8d600 which belongs to the cache mm_struct of size 2584 The buggy address is located 44 bytes inside of freed 2584-byte region [ffff88803fb8d600, ffff88803fb8e018) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803fb8d600 pfn:0x3fb88 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000240(workingset|head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000240 ffff88801a04bb40 ffff888030402b88 ffffea0000fef010 raw: ffff88803fb8d600 00000000000b0001 00000000f5000000 0000000000000000 head: 04fff00000000240 ffff88801a04bb40 ffff888030402b88 ffffea0000fef010 head: ffff88803fb8d600 00000000000b0001 00000000f5000000 0000000000000000 head: 04fff00000000003 ffffea0000fee201 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5022, tgid 5022 (dhcpcd), ts 65839764550, free_ts 65778712810 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0xbeb/0x1420 mm/slub.c:3901 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4247 dup_mm kernel/fork.c:1476 [inline] copy_mm+0xdb/0x4b0 kernel/fork.c:1538 copy_process+0x1706/0x3c00 kernel/fork.c:2180 kernel_clone+0x21e/0x840 kernel/fork.c:2610 __do_sys_clone kernel/fork.c:2753 [inline] __se_sys_clone kernel/fork.c:2737 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2737 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5205 tgid 5205 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 __slab_free+0x303/0x3c0 mm/slub.c:4606 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 vm_area_dup+0x2b/0x680 mm/vma_init.c:122 __split_vma+0x1a9/0xa00 mm/vma.c:515 vms_gather_munmap_vmas+0x2ea/0x12f0 mm/vma.c:1359 __mmap_prepare mm/vma.c:2359 [inline] __mmap_region mm/vma.c:2651 [inline] mmap_region+0x724/0x20c0 mm/vma.c:2739 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803fb8d500: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff88803fb8d580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88803fb8d600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803fb8d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803fb8d700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================