================================================================== BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:-1 [inline] BUG: KASAN: use-after-free in __ext4_iget+0x381/0x44c0 fs/ext4/inode.c:4805 Read of size 8 at addr ffff88812c05feb8 by task syz.8.657/3061 CPU: 0 PID: 3061 Comm: syz.8.657 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 check_igot_inode fs/ext4/inode.c:-1 [inline] __ext4_iget+0x381/0x44c0 fs/ext4/inode.c:4805 ext4_quota_enable fs/ext4/super.c:6451 [inline] ext4_enable_quotas+0x33c/0x6d0 fs/ext4/super.c:6487 ext4_fill_super+0x84ad/0x8d70 fs/ext4/super.c:5064 mount_bdev+0x28b/0x3a0 fs/super.c:1442 ext4_mount+0x34/0x40 fs/ext4/super.c:6666 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1572 do_new_mount+0x25a/0xa20 fs/namespace.c:3006 path_mount+0x585/0xc90 fs/namespace.c:3336 do_mount fs/namespace.c:3349 [inline] __do_sys_mount fs/namespace.c:3557 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3534 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3534 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc6ad7620ca Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc6ac1bae58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc6ac1baee0 RCX: 00007fc6ad7620ca RDX: 00002000000006c0 RSI: 0000200000000640 RDI: 00007fc6ac1baea0 RBP: 00002000000006c0 R08: 00007fc6ac1baee0 R09: 000000000380000a R10: 000000000380000a R11: 0000000000000246 R12: 0000200000000640 R13: 00007fc6ac1baea0 R14: 0000000000000548 R15: 0000200000000700 Allocated by task 2751: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x162/0x2d0 mm/slub.c:2965 kmem_cache_zalloc include/linux/slab.h:657 [inline] ext4_init_io_end+0x29/0x130 fs/ext4/page-io.c:281 ext4_writepages+0xc3d/0x2eb0 fs/ext4/inode.c:2841 do_writepages+0x128/0x280 mm/page-writeback.c:2380 __filemap_fdatawrite_range+0x2a0/0x350 mm/filemap.c:427 file_write_and_wait_range+0x8c/0x110 mm/filemap.c:766 ext4_sync_file+0x1a9/0x9f0 fs/ext4/fsync.c:151 vfs_fsync_range fs/sync.c:202 [inline] vfs_fsync fs/sync.c:216 [inline] do_fsync fs/sync.c:226 [inline] __do_sys_fdatasync fs/sync.c:240 [inline] __se_sys_fdatasync fs/sync.c:238 [inline] __x64_sys_fdatasync+0xb8/0x140 fs/sync.c:238 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 375: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kmem_cache_free+0x100/0x2d0 mm/slub.c:3224 ext4_release_io_end+0x275/0x2c0 fs/ext4/page-io.c:167 ext4_end_io_end fs/ext4/page-io.c:197 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:262 [inline] ext4_end_io_rsv_work+0x4f3/0x610 fs/ext4/page-io.c:276 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff88812c05fea0 which belongs to the cache ext4_io_end of size 64 The buggy address is located 24 bytes inside of 64-byte region [ffff88812c05fea0, ffff88812c05fee0) The buggy address belongs to the page: page:ffffea0004b017c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12c05f flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea0004b0e280 0000000400000004 ffff8881029c2c00 raw: 0000000000000000 00000000002a002a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x112cd0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 375, ts 44944227686, free_ts 43152855587 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x1ac/0x2d0 mm/slub.c:2965 kmem_cache_zalloc include/linux/slab.h:657 [inline] ext4_init_io_end+0x29/0x130 fs/ext4/page-io.c:281 ext4_writepages+0xc3d/0x2eb0 fs/ext4/inode.c:2841 do_writepages+0x128/0x280 mm/page-writeback.c:2380 __writeback_single_inode+0xd5/0xa20 fs/fs-writeback.c:1470 writeback_sb_inodes+0x8ca/0x1480 fs/fs-writeback.c:1733 wb_writeback+0x403/0xbe0 fs/fs-writeback.c:1908 wb_do_writeback fs/fs-writeback.c:2053 [inline] wb_workfn+0x3ac/0xf30 fs/fs-writeback.c:2094 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5445 [inline] __free_pages+0xd8/0x3b0 mm/page_alloc.c:5454 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x15f/0x190 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x162/0x2d0 mm/slub.c:2965 getname_flags+0xb9/0x500 fs/namei.c:141 user_path_at_empty+0x2f/0x50 fs/namei.c:2748 do_readlinkat+0xd9/0x490 fs/stat.c:414 Memory state around the buggy address: ffff88812c05fd80: fa fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb ffff88812c05fe00: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb >ffff88812c05fe80: fc fc fc fc fa fb fb fb fb fb fb fb fc fc fc fc ^ ffff88812c05ff00: fa fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb ffff88812c05ff80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== EXT4-fs error (device loop8): ext4_quota_enable:6451: inode #3: comm syz.8.657: unexpected EA_INODE flag EXT4-fs error (device loop8): ext4_quota_enable:6454: comm syz.8.657: Bad quota inode: 3, type: 0 EXT4-fs warning (device loop8): ext4_enable_quotas:6495: Failed to enable quota tracking (type=0, err=-117, ino=3). Please run e2fsck to fix. EXT4-fs (loop8): mount failed