EXT4-fs error (device loop5): mb_free_blocks:1524: group 0, inode 20: block 241:freeing already freed block (bit 15); block bitmap corrupt.
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BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2596 [inline]
BUG: KASAN: use-after-free in ext4_ext_remove_space+0x3a6a/0x4920 fs/ext4/extents.c:2934
Read of size 4 at addr ffff888119340c18 by task syz-executor/482

CPU: 1 PID: 482 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 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_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_ext_rm_leaf fs/ext4/extents.c:2596 [inline]
 ext4_ext_remove_space+0x3a6a/0x4920 fs/ext4/extents.c:2934
 ext4_ext_truncate+0x169/0x1f0 fs/ext4/extents.c:4467
 ext4_truncate+0xaea/0x1290 fs/ext4/inode.c:4367
 ext4_evict_inode+0xf4f/0x1760 fs/ext4/inode.c:290
 evict+0x478/0x910 fs/inode.c:612
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 do_unlinkat+0x33f/0x670 fs/namei.c:4042
 __do_sys_unlink fs/namei.c:4082 [inline]
 __se_sys_unlink fs/namei.c:4080 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4080
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f6f95dccf17
Code: 73 01 c3 48 c7 c1 a8 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 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffcbbb9aa8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6f95dccf17
RDX: 00007fffcbbb9ad0 RSI: 00007fffcbbb9b60 RDI: 00007fffcbbb9b60
RBP: 00007fffcbbb9b60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fffcbbbac50
R13: 00007f6f95e4f89d R14: 000000000000c7ce R15: 00007fffcbbbbd20

Allocated by task 432:
 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:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960
 getname_flags+0xb9/0x500 fs/namei.c:141
 user_path_at_empty+0x2f/0x50 fs/namei.c:2740
 user_path_at include/linux/namei.h:60 [inline]
 vfs_statx+0xff/0x520 fs/stat.c:193
 vfs_fstatat fs/stat.c:215 [inline]
 __do_sys_newfstatat fs/stat.c:383 [inline]
 __se_sys_newfstatat+0xc6/0x340 fs/stat.c:377
 __x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:377
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 432:
 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:1595 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3219
 putname fs/namei.c:262 [inline]
 filename_lookup+0x459/0x600 fs/namei.c:2470
 user_path_at_empty+0x43/0x50 fs/namei.c:2740
 user_path_at include/linux/namei.h:60 [inline]
 vfs_statx+0xff/0x520 fs/stat.c:193
 vfs_fstatat fs/stat.c:215 [inline]
 __do_sys_newfstatat fs/stat.c:383 [inline]
 __se_sys_newfstatat+0xc6/0x340 fs/stat.c:377
 __x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:377
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888119340000
 which belongs to the cache names_cache of size 4096
The buggy address is located 3096 bytes inside of
 4096-byte region [ffff888119340000, ffff888119341000)
The buggy address belongs to the page:
page:ffffea000464d000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x119340
head:ffffea000464d000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff88810018a480
raw: 0000000000000000 0000000000070007 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 97, ts 4672507038, free_ts 0
 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+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960
 getname_flags+0xb9/0x500 fs/namei.c:141
 getname+0x19/0x20 fs/namei.c:212
 do_sys_openat2+0xd9/0x6d0 fs/open.c:1211
 do_sys_open fs/open.c:1233 [inline]
 __do_sys_openat fs/open.c:1249 [inline]
 __se_sys_openat fs/open.c:1244 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1244
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888119340b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888119340b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888119340c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888119340c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888119340d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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