================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_binsearch fs/ext4/extents.c:837 [inline] BUG: KASAN: slab-use-after-free in ext4_find_extent+0xbc8/0xde0 fs/ext4/extents.c:953 Read of size 4 at addr ffff8880778b8000 by task syz-executor.2/22840 CPU: 0 PID: 22840 Comm: syz-executor.2 Not tainted 6.6.0-syzkaller-00207-g14ab6d425e80 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x175/0x1b0 mm/kasan/report.c:588 ext4_ext_binsearch fs/ext4/extents.c:837 [inline] ext4_find_extent+0xbc8/0xde0 fs/ext4/extents.c:953 ext4_ext_map_blocks+0x2cb/0x7150 fs/ext4/extents.c:4101 ext4_map_blocks+0xa2f/0x1cb0 fs/ext4/inode.c:621 _ext4_get_block+0x238/0x6a0 fs/ext4/inode.c:763 ext4_block_write_begin+0x552/0x1860 fs/ext4/inode.c:1043 ext4_write_begin+0x619/0x10b0 generic_perform_write+0x31b/0x630 mm/filemap.c:3969 ext4_buffered_write_iter+0xc6/0x350 fs/ext4/file.c:299 ext4_file_write_iter+0x1d3/0x1ad0 fs/ext4/file.c:717 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x792/0xb20 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7feafe47cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007feaff2950c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007feafe59bf80 RCX: 00007feafe47cae9 RDX: 000000006db6e559 RSI: 00000000200001c0 RDI: 0000000000000008 RBP: 00007feafe4c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007feafe59bf80 R15: 00007ffc71282278 Allocated by task 4482: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1026 [inline] __kmalloc+0xb9/0x230 mm/slab_common.c:1039 kmalloc include/linux/slab.h:603 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x730 security/tomoyo/file.c:822 security_inode_getattr+0xd3/0x120 security/security.c:2153 vfs_getattr+0x2a/0x3a0 fs/stat.c:169 vfs_fstat fs/stat.c:194 [inline] vfs_fstatat+0xd6/0x190 fs/stat.c:291 __do_sys_newfstatat fs/stat.c:459 [inline] __se_sys_newfstatat fs/stat.c:453 [inline] __x64_sys_newfstatat+0x117/0x190 fs/stat.c:453 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 4482: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0x25f/0x3b0 mm/slub.c:3822 tomoyo_realpath_from_path+0x5a3/0x5e0 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x730 security/tomoyo/file.c:822 security_inode_getattr+0xd3/0x120 security/security.c:2153 vfs_getattr+0x2a/0x3a0 fs/stat.c:169 vfs_fstat fs/stat.c:194 [inline] vfs_fstatat+0xd6/0x190 fs/stat.c:291 __do_sys_newfstatat fs/stat.c:459 [inline] __se_sys_newfstatat fs/stat.c:453 [inline] __x64_sys_newfstatat+0x117/0x190 fs/stat.c:453 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff8880778b8000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes inside of freed 4096-byte region [ffff8880778b8000, ffff8880778b9000) The buggy address belongs to the physical page: page:ffffea0001de2e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x778b8 head:ffffea0001de2e00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012842140 dead000000000100 dead000000000122 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 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5068, tgid 5068 (syz-executor.4), ts 340788148813, free_ts 340616940454 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0x31db/0x3360 mm/page_alloc.c:3170 __alloc_pages+0x255/0x670 mm/page_alloc.c:4426 alloc_slab_page+0x6a/0x160 mm/slub.c:1870 allocate_slab mm/slub.c:2017 [inline] new_slab+0x84/0x2f0 mm/slub.c:2070 ___slab_alloc+0xc85/0x1310 mm/slub.c:3223 __slab_alloc mm/slub.c:3322 [inline] __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x1af/0x270 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1025 [inline] __kmalloc+0xa8/0x230 mm/slab_common.c:1039 kmalloc include/linux/slab.h:603 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x730 security/tomoyo/file.c:822 tomoyo_path_unlink+0xd0/0x110 security/tomoyo/tomoyo.c:161 security_path_unlink+0xdb/0x130 security/security.c:1767 do_unlinkat+0x3e6/0x830 fs/namei.c:4379 __do_sys_unlink fs/namei.c:4430 [inline] __se_sys_unlink fs/namei.c:4428 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4428 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1136 [inline] free_unref_page_prepare+0x8c3/0x9f0 mm/page_alloc.c:2312 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2405 discard_slab mm/slub.c:2116 [inline] __unfreeze_partials+0x1dc/0x220 mm/slub.c:2655 put_cpu_partial+0x17b/0x250 mm/slub.c:2731 __slab_free+0x2b6/0x390 mm/slub.c:3679 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x67/0x3d0 mm/slab.h:762 slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x123/0x300 mm/slub.c:3502 kmem_cache_zalloc include/linux/slab.h:710 [inline] alloc_buffer_head+0x2d/0x2a0 fs/buffer.c:3023 folio_alloc_buffers+0x3a9/0x9b0 fs/buffer.c:935 grow_dev_page fs/buffer.c:1072 [inline] grow_buffers fs/buffer.c:1118 [inline] __getblk_slow fs/buffer.c:1145 [inline] __getblk_gfp+0x2d2/0x630 fs/buffer.c:1439 __getblk include/linux/buffer_head.h:399 [inline] do_journal_end+0x100d/0x4770 fs/reiserfs/journal.c:4077 do_journal_release+0x178/0x4d0 fs/reiserfs/journal.c:1916 journal_release+0x1f/0x30 fs/reiserfs/journal.c:1970 Memory state around the buggy address: ffff8880778b7f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880778b7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880778b8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880778b8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880778b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================