================================================================== BUG: KASAN: slab-out-of-bounds in dtInsertEntry+0xd74/0x1270 fs/jfs/jfs_dtree.c:3753 Read of size 4 at addr ffff888071d9120c by task syz.4.37/4609 CPU: 0 PID: 4609 Comm: syz.4.37 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 dtInsertEntry+0xd74/0x1270 fs/jfs/jfs_dtree.c:3753 dtSplitPage+0x24f0/0x31f0 fs/jfs/jfs_dtree.c:1596 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x100e/0x5950 fs/jfs/jfs_dtree.c:871 jfs_mkdir+0x758/0xad0 fs/jfs/namei.c:270 vfs_mkdir+0x387/0x570 fs/namei.c:4114 do_mkdirat+0x1d8/0x440 fs/namei.c:4139 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fae36b9b607 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007fae37afde58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fae37afdee0 RCX: 00007fae36b9b607 RDX: 00000000000001ff RSI: 00002000000001c0 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000200000000140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000001c0 R13: 00007fae37afdea0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4584: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] jfs_alloc_inode+0x24/0x60 fs/jfs/super.c:105 alloc_inode fs/inode.c:261 [inline] iget_locked+0x1a9/0x830 fs/inode.c:1373 jfs_iget+0x20/0x3f0 fs/jfs/inode.c:29 jfs_lookup+0x21d/0x420 fs/jfs/namei.c:1469 __lookup_slow+0x29d/0x3f0 fs/namei.c:1698 lookup_slow+0x53/0x70 fs/namei.c:1715 walk_component+0x2be/0x3f0 fs/namei.c:2006 lookup_last fs/namei.c:2463 [inline] path_lookupat+0x169/0x440 fs/namei.c:2487 filename_lookup+0x224/0x560 fs/namei.c:2516 user_path_at_empty+0x3e/0x60 fs/namei.c:2913 user_path_at include/linux/namei.h:57 [inline] __do_sys_chdir fs/open.c:514 [inline] __se_sys_chdir+0x98/0x280 fs/open.c:508 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888071d90940 which belongs to the cache jfs_ip of size 2240 The buggy address is located 12 bytes to the right of 2240-byte region [ffff888071d90940, ffff888071d91200) The buggy address belongs to the physical page: page:ffffea0001c76400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x71d90 head:ffffea0001c76400 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88807d9d7201 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888147aa8a00 raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff88807d9d7201 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 4584, tgid 4583 (syz.4.37), ts 110539436391, free_ts 98483093698 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x1ae/0x2e0 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] jfs_alloc_inode+0x24/0x60 fs/jfs/super.c:105 alloc_inode fs/inode.c:261 [inline] iget_locked+0x1a9/0x830 fs/inode.c:1373 jfs_iget+0x20/0x3f0 fs/jfs/inode.c:29 jfs_fill_super+0x70e/0xad0 fs/jfs/super.c:580 mount_bdev+0x287/0x3c0 fs/super.c:1443 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x24a/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1486 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] __kmem_cache_alloc_node+0x140/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] tomoyo_realpath_from_path+0xdf/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x26f/0x610 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x120 security/security.c:1361 vfs_getattr+0x26/0x3a0 fs/stat.c:158 vfs_fstat fs/stat.c:183 [inline] __do_sys_newfstat fs/stat.c:447 [inline] __se_sys_newfstat fs/stat.c:444 [inline] __x64_sys_newfstat+0x13d/0x220 fs/stat.c:444 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 Memory state around the buggy address: ffff888071d91100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888071d91180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888071d91200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888071d91280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888071d91300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================