================================================================== BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2601 [inline] BUG: KASAN: use-after-free in ext4_ext_remove_space+0x3496/0x40d0 fs/ext4/extents.c:2939 Read of size 4 at addr ffff8881295eac18 by task syz-executor/356 CPU: 0 PID: 356 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_rm_leaf fs/ext4/extents.c:2601 [inline] ext4_ext_remove_space+0x3496/0x40d0 fs/ext4/extents.c:2939 ext4_ext_truncate+0x1a3/0x250 fs/ext4/extents.c:4473 ext4_truncate+0x9be/0xfb0 fs/ext4/inode.c:4287 ext4_evict_inode+0xcc5/0x1460 fs/ext4/inode.c:290 evict+0x4c9/0x8d0 fs/inode.c:650 iput_final fs/inode.c:1779 [inline] iput+0x635/0x7c0 fs/inode.c:1805 do_unlinkat+0x380/0x6d0 fs/namei.c:4363 __do_sys_unlink fs/namei.c:4404 [inline] __se_sys_unlink fs/namei.c:4402 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4402 x64_sys_call+0x878/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:88 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe4017c2887 Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007fffc33caa58 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe4017c2887 RDX: 00007fffc33caa80 RSI: 00007fffc33cab10 RDI: 00007fffc33cab10 RBP: 00007fffc33cab10 R08: 00007fffc33cbb10 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007fffc33cbc00 R13: 00007fe401858f90 R14: 000000000000631e R15: 00007fffc33cccd0 The buggy address belongs to the page: page:ffffea0004a57a80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x100 pfn:0x1295ea flags: 0x4000000000000000(zone=1) raw: 4000000000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000100 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 289, ts 23400433336, free_ts 23431510867 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2d3a/0x2dc0 mm/page_alloc.c:4485 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5808 __alloc_pages_node include/linux/gfp.h:595 [inline] alloc_pages_node include/linux/gfp.h:609 [inline] alloc_pages include/linux/gfp.h:622 [inline] do_anonymous_page mm/memory.c:4069 [inline] handle_pte_fault+0xebf/0x2710 mm/memory.c:4909 __handle_mm_fault mm/memory.c:-1 [inline] do_handle_mm_fault+0x1af9/0x1de0 mm/memory.c:5333 handle_mm_fault include/linux/mm.h:1847 [inline] do_user_addr_fault+0x828/0x1250 arch/x86/mm/fault.c:1416 handle_page_fault arch/x86/mm/fault.c:1507 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1560 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare mm/page_alloc.c:1544 [inline] free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534 free_unref_page_list+0x13a/0x9d0 mm/page_alloc.c:3671 release_pages+0x1006/0x1060 mm/swap.c:1015 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:320 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x17e/0x310 mm/mmu_gather.c:338 unmap_region+0x344/0x3b0 mm/mmap.c:2692 __do_munmap+0xa24/0x1020 mm/mmap.c:2925 __vm_munmap+0x163/0x2b0 mm/mmap.c:2978 __do_sys_munmap mm/mmap.c:3004 [inline] __se_sys_munmap mm/mmap.c:3000 [inline] __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3000 x64_sys_call+0xc9/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff8881295eab00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881295eab80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881295eac00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881295eac80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881295ead00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 125754167125696, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 125754167096165, count = 29541 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 125754167096160, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 104678896035552, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 104678896005751, count = 29816 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 104678896005744, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 127953340382912, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 127953340358512, count = 24404 EXT4-fs error: 36266 callbacks suppressed EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589990710464, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589990684262, count = 26214 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589990684256, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 129074041152876, count = 28525 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 129074041152864, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 53014410877520, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 53014410851360, count = 26166 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 53014410851360, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589990710464, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589990684262, count = 26214 EXT4-fs error: 41028 callbacks suppressed EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589148835008, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589148808806, count = 26214 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 112589148808800, count = 16