================================================================== BUG: KASAN: use-after-free in btrfs_sb fs/btrfs/super.h:14 [inline] BUG: KASAN: use-after-free in wait_subpage_spinlock+0x1be/0x210 fs/btrfs/inode.c:8232 Read of size 8 at addr ffff8880231fe678 by task syz-executor.1/13741 CPU: 3 PID: 13741 Comm: syz-executor.1 Not tainted 6.2.0-rc3-syzkaller-00008-g1fe4fd6f5cad #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517 btrfs_sb fs/btrfs/super.h:14 [inline] wait_subpage_spinlock+0x1be/0x210 fs/btrfs/inode.c:8232 __btrfs_release_folio fs/btrfs/inode.c:8261 [inline] btrfs_release_folio+0x109/0x130 fs/btrfs/inode.c:8271 filemap_release_folio+0x13f/0x1b0 mm/filemap.c:3967 shrink_folio_list+0x1ea9/0x3a60 mm/vmscan.c:2000 shrink_inactive_list mm/vmscan.c:2526 [inline] shrink_list mm/vmscan.c:2767 [inline] shrink_lruvec+0xd0e/0x27a0 mm/vmscan.c:5951 shrink_node_memcgs mm/vmscan.c:6138 [inline] shrink_node+0x8f2/0x1f40 mm/vmscan.c:6169 shrink_zones mm/vmscan.c:6407 [inline] do_try_to_free_pages+0x3b4/0x17a0 mm/vmscan.c:6469 try_to_free_pages+0x2e5/0x960 mm/vmscan.c:6704 __perform_reclaim mm/page_alloc.c:4750 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:4772 [inline] __alloc_pages_slowpath.constprop.0+0x8b6/0x23d0 mm/page_alloc.c:5178 __alloc_pages+0x4aa/0x5b0 mm/page_alloc.c:5562 __folio_alloc+0x16/0x40 mm/page_alloc.c:5581 vma_alloc_folio+0x155/0x870 mm/mempolicy.c:2247 shmem_alloc_folio+0xfe/0x1d0 mm/shmem.c:1571 shmem_alloc_and_acct_folio+0x15e/0x5d0 mm/shmem.c:1595 shmem_get_folio_gfp+0xb2e/0x1a30 mm/shmem.c:1922 shmem_get_folio mm/shmem.c:2053 [inline] shmem_write_begin+0x14a/0x380 mm/shmem.c:2545 generic_perform_write+0x256/0x570 mm/filemap.c:3772 __generic_file_write_iter+0x2ae/0x500 mm/filemap.c:3900 generic_file_write_iter+0xe3/0x350 mm/filemap.c:3932 call_write_iter include/linux/fs.h:2189 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9ed/0xdd0 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7fb7549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7fb23c0 EFLAGS: 00000282 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000ed9ff000 RDX: 0000000002000000 RSI: 00000000f734d000 RDI: 0000000000000000 RBP: 00000000f7fb2480 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4594: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] kernfs_iop_get_link fs/kernfs/symlink.c:135 [inline] kernfs_iop_get_link+0x6e/0x730 fs/kernfs/symlink.c:126 vfs_readlink+0x1db/0x390 fs/namei.c:5026 do_readlinkat+0x27e/0x2f0 fs/stat.c:483 __do_sys_readlink fs/stat.c:504 [inline] __se_sys_readlink fs/stat.c:501 [inline] __x64_sys_readlink+0x78/0xb0 fs/stat.c:501 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 4594: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3800 do_delayed_call include/linux/delayed_call.h:28 [inline] vfs_readlink+0x146/0x390 fs/namei.c:5031 do_readlinkat+0x27e/0x2f0 fs/stat.c:483 __do_sys_readlink fs/stat.c:504 [inline] __se_sys_readlink fs/stat.c:501 [inline] __x64_sys_readlink+0x78/0xb0 fs/stat.c:501 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x693/0x13b0 kernel/workqueue.c:1517 queue_work_on+0xf2/0x110 kernel/workqueue.c:1545 rcu_do_batch kernel/rcu/tree.c:2246 [inline] rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2506 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 __call_rcu_common.constprop.0+0x99/0x820 kernel/rcu/tree.c:2755 __put_super fs/super.c:347 [inline] put_super fs/super.c:311 [inline] deactivate_locked_super+0x142/0x160 fs/super.c:343 deactivate_super+0xb1/0xd0 fs/super.c:363 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 The buggy address belongs to the object at ffff8880231fe000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1656 bytes inside of 4096-byte region [ffff8880231fe000, ffff8880231ff000) The buggy address belongs to the physical page: page:ffffea00008c7e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x231f8 head:ffffea00008c7e00 order:3 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012443040 ffffea0000678a00 dead000000000002 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 8518, tgid 8518 (udevadm), ts 276516656011, free_ts 224314987620 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x1a4/0x430 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc+0x4a/0xd0 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] tomoyo_realpath_from_path+0xc3/0x600 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x297/0x3a0 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:332 [inline] tomoyo_file_open+0xa1/0xc0 security/tomoyo/tomoyo.c:327 security_file_open+0x49/0xb0 security/security.c:1718 do_dentry_open+0x575/0x13f0 fs/open.c:869 do_open fs/namei.c:3557 [inline] path_openat+0x1bbc/0x2a50 fs/namei.c:3714 do_filp_open+0x1ba/0x410 fs/namei.c:3741 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare+0x65c/0xc00 mm/page_alloc.c:1496 free_unref_page_prepare mm/page_alloc.c:3369 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3464 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:761 [inline] slab_alloc_node mm/slub.c:3452 [inline] __kmem_cache_alloc_node+0x1ea/0x430 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc+0x4a/0xd0 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] tomoyo_realpath_from_path+0xc3/0x600 security/tomoyo/realpath.c:251 tomoyo_realpath_nofollow+0xcc/0xe0 security/tomoyo/realpath.c:304 tomoyo_find_next_domain+0x284/0x1f80 security/tomoyo/domain.c:727 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:101 [inline] tomoyo_bprm_check_security+0x133/0x1c0 security/tomoyo/tomoyo.c:91 security_bprm_check+0x49/0xb0 security/security.c:897 search_binary_handler fs/exec.c:1723 [inline] exec_binprm fs/exec.c:1777 [inline] bprm_execve fs/exec.c:1851 [inline] bprm_execve+0x732/0x19f0 fs/exec.c:1808 kernel_execve+0x3ee/0x500 fs/exec.c:2016 call_usermodehelper_exec_async+0x2e7/0x580 kernel/umh.c:113 Memory state around the buggy address: ffff8880231fe500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880231fe580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880231fe600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880231fe680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880231fe700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi