================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xc1f/0xc30 fs/ext4/xattr.c:2911 Read of size 4 at addr ffff8881e8b67000 by task syz-executor.3/1754 CPU: 1 PID: 1754 Comm: syz-executor.3 Not tainted 5.4.274-syzkaller-00002-g6f97bd951d82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x600 mm/kasan/report.c:384 __kasan_report+0xf3/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 ext4_xattr_delete_inode+0xc1f/0xc30 fs/ext4/xattr.c:2911 ext4_evict_inode+0x1378/0x1ac0 fs/ext4/inode.c:318 evict+0x29b/0x6a0 fs/inode.c:575 d_delete_notify include/linux/fsnotify.h:224 [inline] vfs_rmdir+0x24b/0x3c0 fs/namei.c:4040 do_rmdir+0x2c1/0x580 fs/namei.c:4088 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f918cacd707 Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff1d7167e8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f918cacd707 RDX: 0000000000000200 RSI: 00007fff1d717990 RDI: 00000000ffffff9c RBP: 00007f918cb2a6c6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007fff1d717990 R13: 00007f918cb2a6c6 R14: 00000000000115eb R15: 0000000000000007 Allocated by task 465: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842 kmem_cache_zalloc include/linux/slab.h:680 [inline] locks_alloc_lock fs/locks.c:346 [inline] flock_make_lock fs/locks.c:487 [inline] __do_sys_flock fs/locks.c:2234 [inline] __se_sys_flock+0x15a/0x5a0 fs/locks.c:2215 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Freed by task 465: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook mm/slub.c:1494 [inline] slab_free mm/slub.c:3080 [inline] kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096 locks_free_lock fs/locks.c:383 [inline] __do_sys_flock fs/locks.c:2255 [inline] __se_sys_flock+0x494/0x5a0 fs/locks.c:2215 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 The buggy address belongs to the object at ffff8881e8b67000 which belongs to the cache file_lock_cache of size 248 The buggy address is located 0 bytes inside of 248-byte region [ffff8881e8b67000, ffff8881e8b670f8) The buggy address belongs to the page: page:ffffea0007a2d9c0 refcount:1 mapcount:0 mapping:ffff8881f5e78c80 index:0x0 flags: 0x8000000000000200(slab) raw: 8000000000000200 ffffea0007661d40 0000000300000003 ffff8881f5e78c80 raw: 0000000000000000 00000000000d000d 00000001ffffffff 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893 alloc_slab_page+0x39/0x3c0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x97/0x440 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x2fe/0x490 mm/slub.c:2667 __slab_alloc+0x62/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0x109/0x250 mm/slub.c:2842 kmem_cache_zalloc include/linux/slab.h:680 [inline] locks_alloc_lock fs/locks.c:346 [inline] flock_make_lock fs/locks.c:487 [inline] __do_sys_flock fs/locks.c:2234 [inline] __se_sys_flock+0x15a/0x5a0 fs/locks.c:2215 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1176 [inline] free_pcp_prepare mm/page_alloc.c:1233 [inline] free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085 free_unref_page mm/page_alloc.c:3134 [inline] free_the_page mm/page_alloc.c:4953 [inline] __free_pages mm/page_alloc.c:4961 [inline] free_pages+0x114/0x1b0 mm/page_alloc.c:4969 tlb_batch_list_free mm/mmu_gather.c:61 [inline] tlb_finish_mmu+0x249/0x320 mm/mmu_gather.c:280 exit_mmap+0x2dc/0x520 mm/mmap.c:3193 __mmput+0x8e/0x2c0 kernel/fork.c:1101 exit_mm kernel/exit.c:536 [inline] do_exit+0xc08/0x2bc0 kernel/exit.c:846 do_group_exit+0x138/0x300 kernel/exit.c:982 get_signal+0xdb1/0x1440 kernel/signal.c:2735 do_signal+0xb0/0x11f0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc0/0x1a0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881e8b66f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881e8b66f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881e8b67000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881e8b67080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ffff8881e8b67100: fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb fb ==================================================================