================================================================== BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x10d4/0x31d0 fs/jfs/jfs_dtree.c:-1 Read of size 1 at addr ffff888060dec0b5 by task syz.1.9/4361 CPU: 1 PID: 4361 Comm: syz.1.9 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 dtSplitPage+0x10d4/0x31d0 fs/jfs/jfs_dtree.c:-1 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0xfb2/0x57a0 fs/jfs/jfs_dtree.c:871 jfs_mkdir+0x6e5/0xa70 fs/jfs/namei.c:270 vfs_mkdir+0x387/0x570 fs/namei.c:4065 do_mkdirat+0x1d7/0x5a0 fs/namei.c:4090 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103 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: 0033:0x7fd9bd345ba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd9bb56b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fd9bd58d180 RCX: 00007fd9bd345ba9 RDX: 00000000000001c0 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007fd9bd3c8e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd9bd58d218 R14: 00007fd9bd58d180 R15: 00007fff7607e288 Allocated by task 4343: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 jfs_alloc_inode+0x17/0x50 fs/jfs/super.c:105 alloc_inode fs/inode.c:261 [inline] iget_locked+0x191/0x820 fs/inode.c:1308 jfs_iget+0x20/0x3c0 fs/jfs/inode.c:29 jfs_lookup+0x1c2/0x380 fs/jfs/namei.c:1467 __lookup_slow+0x27d/0x3d0 fs/namei.c:1663 lookup_slow+0x53/0x70 fs/namei.c:1680 walk_component+0x319/0x460 fs/namei.c:1976 lookup_last fs/namei.c:2431 [inline] path_lookupat+0x169/0x440 fs/namei.c:2455 filename_lookup+0x1e2/0x4f0 fs/namei.c:2484 user_path_at_empty+0x40/0x190 fs/namei.c:2883 user_path_at include/linux/namei.h:57 [inline] __do_sys_chdir fs/open.c:490 [inline] __se_sys_chdir+0x91/0x280 fs/open.c:484 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 The buggy address belongs to the object at ffff888060deb780 which belongs to the cache jfs_ip of size 2240 The buggy address is located 117 bytes to the right of 2240-byte region [ffff888060deb780, ffff888060dec040) The buggy address belongs to the page: page:ffffea0001837a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x60de8 head:ffffea0001837a00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88802a710101 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88814685adc0 raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff88802a710101 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 4343, ts 85032263288, free_ts 21136020378 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x195/0x290 mm/slub.c:3238 jfs_alloc_inode+0x17/0x50 fs/jfs/super.c:105 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x5f/0x210 fs/inode.c:1001 new_inode+0x25/0x1c0 fs/inode.c:1030 jfs_fill_super+0x392/0xaf0 fs/jfs/super.c:549 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3025 do_mount fs/namespace.c:3368 [inline] __do_sys_mount fs/namespace.c:3576 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553 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 last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 free_contig_range+0x96/0xf0 mm/page_alloc.c:9406 destroy_args+0x100/0xa20 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x318/0x370 mm/debug_vm_pgtable.c:1336 do_one_initcall+0x1ee/0x680 init/main.c:1302 do_initcall_level+0x137/0x1f0 init/main.c:1375 do_initcalls+0x4b/0x90 init/main.c:1391 kernel_init_freeable+0x3ce/0x560 init/main.c:1615 kernel_init+0x19/0x1b0 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff888060debf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888060dec000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff888060dec080: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ^ ffff888060dec100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888060dec180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================