EXT4-fs (loop2): pa ffff8881311a2dc8: logic 128, phys. 385, len 8 EXT4-fs error (device loop2): ext4_mb_release_inode_pa:4902: group 0, free 0, pa_free 1 ================================================================== 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 ffff888131034c18 by task syz.2.19/404 CPU: 0 PID: 404 Comm: syz.2.19 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:4479 ext4_truncate+0x9be/0xfb0 fs/ext4/inode.c:4287 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline] ext4_write_begin+0xad4/0x12e0 fs/ext4/inode.c:1276 ext4_da_write_begin+0x321/0xbf0 fs/ext4/inode.c:2988 generic_perform_write+0x2b7/0x690 mm/filemap.c:3870 ext4_buffered_write_iter+0x4ed/0x670 fs/ext4/file.c:270 ext4_file_write_iter+0x440/0x1540 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2212 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x835/0xfd0 fs/read_write.c:594 ksys_pwrite64 fs/read_write.c:701 [inline] __do_sys_pwrite64 fs/read_write.c:711 [inline] __se_sys_pwrite64 fs/read_write.c:708 [inline] __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:708 x64_sys_call+0xa6/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:19 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: 0033:0x7f95c8d02799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f95c8b65028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f95c8f7bfa0 RCX: 00007f95c8d02799 RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007f95c8d98c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000009000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95c8f7c038 R14: 00007f95c8f7bfa0 R15: 00007ffc516966c8 Allocated by task 364: 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:433 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 sock_alloc_inode+0x1b/0xb0 net/socket.c:303 alloc_inode fs/inode.c:264 [inline] new_inode_pseudo+0x62/0x210 fs/inode.c:1011 sock_alloc net/socket.c:626 [inline] __sock_create+0x12c/0x7a0 net/socket.c:1449 sock_create net/socket.c:1541 [inline] __sys_socket+0xec/0x190 net/socket.c:1583 __do_sys_socket net/socket.c:1592 [inline] __se_sys_socket net/socket.c:1590 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1590 x64_sys_call+0x8c5/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:42 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 Freed by task 321: 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:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3544 sock_free_inode+0x20/0x30 net/socket.c:324 i_callback+0x4c/0x70 fs/inode.c:253 rcu_do_batch+0x532/0xbe0 kernel/rcu/tree.c:2523 rcu_core+0x5ee/0xf80 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 __do_softirq+0xb/0xd kernel/softirq.c:621 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu_common kernel/rcu/tree.c:3011 [inline] call_rcu+0x10b/0xf80 kernel/rcu/tree.c:3129 destroy_inode fs/inode.c:319 [inline] evict+0x834/0x8d0 fs/inode.c:665 iput_final fs/inode.c:1779 [inline] iput+0x635/0x7c0 fs/inode.c:1805 dentry_unlink_inode+0x32f/0x3e0 fs/dcache.c:380 __dentry_kill+0x44f/0x650 fs/dcache.c:586 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x47/0x90 fs/dcache.c:893 __fput+0x580/0x8b0 fs/file_table.c:319 ____fput+0x15/0x20 fs/file_table.c:339 task_work_run+0x127/0x190 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888131034c00 which belongs to the cache sock_inode_cache of size 896 The buggy address is located 24 bytes inside of 896-byte region [ffff888131034c00, ffff888131034f80) The buggy address belongs to the page: page:ffffea0004c40d00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131034 head:ffffea0004c40d00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff8881081aa180 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 364, ts 24792880894, free_ts 0 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:5822 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa1/0x4d0 mm/slub.c:2000 ___slab_alloc+0x381/0x810 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3260 sock_alloc_inode+0x1b/0xb0 net/socket.c:303 alloc_inode fs/inode.c:264 [inline] new_inode_pseudo+0x62/0x210 fs/inode.c:1011 sock_alloc net/socket.c:626 [inline] __sock_create+0x12c/0x7a0 net/socket.c:1449 sock_create net/socket.c:1541 [inline] __sys_socket+0xec/0x190 net/socket.c:1583 __do_sys_socket net/socket.c:1592 [inline] __se_sys_socket net/socket.c:1590 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1590 x64_sys_call+0x8c5/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:42 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 page_owner free stack trace missing Memory state around the buggy address: ffff888131034b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888131034b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888131034c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888131034c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888131034d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================