================================================================== BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x1066/0x3200 fs/jfs/jfs_dtree.c:-1 Read of size 1 at addr ffff88806240d2d5 by task syz.0.76/4822 CPU: 0 PID: 4822 Comm: syz.0.76 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 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+0x1066/0x3200 fs/jfs/jfs_dtree.c:-1 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0xff4/0x5830 fs/jfs/jfs_dtree.c:871 jfs_mkdir+0x758/0xad0 fs/jfs/namei.c:270 vfs_mkdir+0x387/0x570 fs/namei.c:4073 do_mkdirat+0x1df/0x5b0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111 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: 0033:0x7f33f5591e57 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:00007f33f37ece58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f33f37ecee0 RCX: 00007f33f5591e57 RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c RBP: 00002000000002c0 R08: 00002000000007c0 R09: 0000000000000000 R10: 00002000000002c0 R11: 0000000000000246 R12: 00002000000000c0 R13: 00007f33f37ecea0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4822: 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+0x20/0x3f0 fs/jfs/inode.c:29 jfs_lookup+0x21d/0x420 fs/jfs/namei.c:1467 __lookup_slow+0x29d/0x410 fs/namei.c:1671 lookup_slow+0x53/0x70 fs/namei.c:1688 walk_component+0x319/0x460 fs/namei.c:1984 lookup_last fs/namei.c:2439 [inline] path_lookupat+0x169/0x440 fs/namei.c:2463 filename_lookup+0x214/0x540 fs/namei.c:2492 user_path_at_empty+0x40/0x190 fs/namei.c:2891 user_path_at include/linux/namei.h:57 [inline] __do_sys_chdir fs/open.c:490 [inline] __se_sys_chdir+0x98/0x280 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 ffff88806240ca00 which belongs to the cache jfs_ip of size 2240 The buggy address is located 21 bytes to the right of 2240-byte region [ffff88806240ca00, ffff88806240d2c0) The buggy address belongs to the page: page:ffffea0001890200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x62408 head:ffffea0001890200 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88805ec3bf01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146b59140 raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff88805ec3bf01 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 4520, ts 66721738923, free_ts 64082174214 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 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+0x80a/0xdd0 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] iget_locked+0x191/0x820 fs/inode.c:1308 jfs_iget+0x20/0x3f0 fs/jfs/inode.c:29 jfs_lookup+0x21d/0x420 fs/jfs/namei.c:1467 lookup_open fs/namei.c:3448 [inline] open_last_lookups fs/namei.c:3540 [inline] path_openat+0x1022/0x2fa0 fs/namei.c:3747 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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+0x8f/0x2a0 mm/page_alloc.c:3396 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 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] __kmalloc_node+0x15a/0x3b0 mm/slub.c:4456 kmalloc_node include/linux/slab.h:630 [inline] kvmalloc_node+0x84/0x130 mm/util.c:619 kvmalloc include/linux/mm.h:816 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x1f6/0xd50 fs/seq_file.c:210 call_read_iter include/linux/fs.h:2167 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x759/0xd60 fs/read_write.c:485 ksys_read+0x152/0x260 fs/read_write.c:623 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: ffff88806240d180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88806240d200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88806240d280: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ^ ffff88806240d300: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88806240d380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================