EXT4-fs (loop4): feature flags set on rev 0 fs, running e2fsck is recommended ================================================================== BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:-1 [inline] BUG: KASAN: use-after-free in __ext4_iget+0x23c/0x32ac fs/ext4/inode.c:4863 Read of size 8 at addr ffff0000e274ad90 by task syz.4.12110/31300 CPU: 1 PID: 31300 Comm: syz.4.12110 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 __asan_report_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351 check_igot_inode fs/ext4/inode.c:-1 [inline] __ext4_iget+0x23c/0x32ac fs/ext4/inode.c:4863 __ext4_fill_super fs/ext4/super.c:5423 [inline] ext4_fill_super+0x4df4/0x660c fs/ext4/super.c:5687 get_tree_bdev+0x358/0x544 fs/super.c:1366 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5717 vfs_get_tree+0x90/0x274 fs/super.c:1573 do_new_mount+0x228/0x810 fs/namespace.c:3078 path_mount+0x5bc/0xe80 fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x49c/0x59c fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 12546: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x430 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x1a4/0x280 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] reiserfs_alloc_inode+0x2c/0xc4 fs/reiserfs/super.c:642 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x68/0x1cc fs/inode.c:1063 new_inode+0x38/0x174 fs/inode.c:1091 reiserfs_mkdir+0x19c/0x7bc fs/reiserfs/namei.c:815 xattr_mkdir fs/reiserfs/xattr.c:76 [inline] create_privroot fs/reiserfs/xattr.c:882 [inline] reiserfs_xattr_init+0x2b0/0x6b4 fs/reiserfs/xattr.c:1005 reiserfs_fill_super+0x1944/0x1d40 fs/reiserfs/super.c:2175 mount_bdev+0x264/0x358 fs/super.c:1443 get_super_block+0x44/0x58 fs/reiserfs/super.c:2601 legacy_get_tree+0xd4/0x16c fs/fs_context.c:632 vfs_get_tree+0x90/0x274 fs/super.c:1573 do_new_mount+0x228/0x810 fs/namespace.c:3078 path_mount+0x5bc/0xe80 fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x49c/0x59c fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:46 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 call_rcu+0x100/0x94c kernel/rcu/tree.c:2849 destroy_inode fs/inode.c:316 [inline] evict+0x760/0x828 fs/inode.c:720 dispose_list fs/inode.c:738 [inline] evict_inodes+0x604/0x6a4 fs/inode.c:792 generic_shutdown_super+0x9c/0x324 fs/super.c:480 kill_block_super+0x70/0xdc fs/super.c:1470 reiserfs_kill_sb+0x124/0x13c fs/reiserfs/super.c:570 deactivate_locked_super+0xac/0x120 fs/super.c:332 deactivate_super+0xe4/0x104 fs/super.c:363 cleanup_mnt+0x390/0x418 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x278 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x1fa0/0x2aa4 arch/arm64/kernel/signal.c:1151 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Second to last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:46 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 call_rcu+0x100/0x94c kernel/rcu/tree.c:2849 destroy_inode fs/inode.c:316 [inline] evict+0x760/0x828 fs/inode.c:720 dispose_list fs/inode.c:738 [inline] evict_inodes+0x604/0x6a4 fs/inode.c:792 generic_shutdown_super+0x9c/0x324 fs/super.c:480 kill_block_super+0x70/0xdc fs/super.c:1470 reiserfs_kill_sb+0x124/0x13c fs/reiserfs/super.c:570 deactivate_locked_super+0xac/0x120 fs/super.c:332 deactivate_super+0xe4/0x104 fs/super.c:363 cleanup_mnt+0x390/0x418 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x278 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x1fa0/0x2aa4 arch/arm64/kernel/signal.c:1151 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the object at ffff0000e274a7c0 which belongs to the cache reiser_inode_cache of size 1568 The buggy address is located 1488 bytes inside of 1568-byte region [ffff0000e274a7c0, ffff0000e274ade0) The buggy address belongs to the physical page: page:00000000c4fa6c8c refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000e274dcc0 pfn:0x122748 head:00000000c4fa6c8c order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff0000d2a3ca01 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 0000000000000000 dead000000000122 ffff0000c4dd3380 raw: ffff0000e274dcc0 0000000080130011 00000001ffffffff ffff0000d2a3ca01 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000e274ac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000e274ad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000e274ad80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff0000e274ae00: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00 ffff0000e274ae80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== EXT4-fs error (device loop4): __ext4_fill_super:5423: inode #2: comm syz.4.12110: unexpected EA_INODE flag EXT4-fs (loop4): get root inode failed EXT4-fs (loop4): mount failed