================================================================== BUG: KASAN: use-after-free in get_max_inline_xattr_value_size+0x369/0x510 fs/ext4/inline.c:61 Read of size 4 at addr ffff8881ecae8004 by task syz-executor.3/10446 CPU: 1 PID: 10446 Comm: syz-executor.3 Not tainted 5.4.242-syzkaller-00001-g14e059a4e07a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 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 get_max_inline_xattr_value_size+0x369/0x510 fs/ext4/inline.c:61 ext4_get_max_inline_size+0x134/0x1f0 fs/ext4/inline.c:112 ext4_try_to_write_inline_data+0xda/0x1720 fs/ext4/inline.c:672 ext4_write_begin+0x25a/0x1900 fs/ext4/inode.c:1314 ext4_da_write_begin+0x4a3/0xfe0 fs/ext4/inode.c:3120 generic_perform_write+0x2c7/0x560 mm/filemap.c:3311 __generic_file_write_iter+0x224/0x530 mm/filemap.c:3440 ext4_file_write_iter+0x499/0x10e0 fs/ext4/file.c:270 call_write_iter include/linux/fs.h:1981 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0x5d3/0x750 fs/read_write.c:496 vfs_write+0x206/0x4e0 fs/read_write.c:558 ksys_write+0x199/0x2c0 fs/read_write.c:611 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Allocated by task 493: 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 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] kvmalloc_node+0x7e/0xf0 mm/util.c:596 kvmalloc include/linux/mm.h:759 [inline] seq_buf_alloc fs/seq_file.c:35 [inline] seq_read+0x23c/0xe60 fs/seq_file.c:207 __vfs_read+0x103/0x730 fs/read_write.c:425 vfs_read+0x148/0x360 fs/read_write.c:461 ksys_read+0x199/0x2c0 fs/read_write.c:587 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Freed by task 493: 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] kfree+0x123/0x370 mm/slub.c:4071 seq_release+0x53/0x70 fs/seq_file.c:363 kernfs_fop_release+0x1b1/0x240 fs/kernfs/file.c:780 __fput+0x262/0x680 fs/file_table.c:281 task_work_run+0x140/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x190/0x1a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 The buggy address belongs to the object at ffff8881ecae8000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 4 bytes inside of 4096-byte region [ffff8881ecae8000, ffff8881ecae9000) The buggy address belongs to the page: page:ffffea0007b2ba00 refcount:1 mapcount:0 mapping:ffff8881f5c0c280 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 ffffea000785ca00 0000000200000002 ffff8881f5c0c280 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL) 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:4891 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_trace+0x12d/0x260 mm/slub.c:2854 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] uevent_show+0x158/0x320 drivers/base/core.c:1938 dev_attr_show+0x50/0xb0 drivers/base/core.c:1647 sysfs_kf_seq_show+0x265/0x3e0 fs/sysfs/file.c:61 seq_read+0x4df/0xe60 fs/seq_file.c:232 __vfs_read+0x103/0x730 fs/read_write.c:425 vfs_read+0x148/0x360 fs/read_write.c:461 ksys_read+0x199/0x2c0 fs/read_write.c:587 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 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_pages_ok+0x847/0x950 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4953 [inline] __free_pages+0x91/0x140 mm/page_alloc.c:4959 __free_slab+0x221/0x2e0 mm/slub.c:1774 free_slab mm/slub.c:1789 [inline] discard_slab mm/slub.c:1795 [inline] unfreeze_partials+0x14e/0x180 mm/slub.c:2288 put_cpu_partial+0x44/0x180 mm/slub.c:2324 __slab_free+0x297/0x360 mm/slub.c:2971 qlist_free_all+0x43/0xb0 mm/kasan/quarantine.c:167 quarantine_reduce+0x1d9/0x210 mm/kasan/quarantine.c:260 __kasan_kmalloc+0x41/0x210 mm/kasan/common.c:507 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 getname_flags+0xb8/0x4e0 fs/namei.c:141 user_path_at_empty+0x28/0x50 fs/namei.c:2683 do_readlinkat+0x114/0x3a0 fs/stat.c:398 __do_sys_readlink fs/stat.c:431 [inline] __se_sys_readlink fs/stat.c:428 [inline] __x64_sys_readlink+0x7b/0x90 fs/stat.c:428 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881ecae7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881ecae7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881ecae8000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ecae8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ecae8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop3): ext4_xattr_ibody_find:2222: inode #18: comm syz-executor.3: corrupted in-inode xattr