================================================================== BUG: KASAN: slab-out-of-bounds in dtInsertEntry+0xd74/0x1270 fs/jfs/jfs_dtree.c:3753 Read of size 4 at addr ffff888072b1c04c by task syz.1.148/4929 CPU: 1 PID: 4929 Comm: syz.1.148 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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_symlink+0x8b2/0xfb0 fs/jfs/namei.c:1019 vfs_symlink+0x247/0x3d0 fs/namei.c:4479 do_symlinkat+0x1b6/0x400 fs/namei.c:4508 __do_sys_symlink fs/namei.c:4530 [inline] __se_sys_symlink fs/namei.c:4528 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4528 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: 0033:0x7f8e79d9bf79 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:00007f8e7ac68028 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007f8e7a016180 RCX: 00007f8e79d9bf79 RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000200000000100 RBP: 00007f8e79e327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8e7a016218 R14: 00007f8e7a016180 R15: 00007ffda90c3168 Allocated by task 4905: 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:1467 __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 ffff888072b1b780 which belongs to the cache jfs_ip of size 2240 The buggy address is located 12 bytes to the right of 2240-byte region [ffff888072b1b780, ffff888072b1c040) The buggy address belongs to the physical page: page:ffffea0001cac600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x72b18 head:ffffea0001cac600 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88802e812a01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88801a308c80 raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff88802e812a01 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 4905, tgid 4904 (syz.1.148), ts 127039866125, free_ts 122538017946 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:5643 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] new_inode_pseudo+0x5f/0x1c0 fs/inode.c:1063 new_inode+0x25/0x1c0 fs/inode.c:1091 jfs_fill_super+0x398/0xad0 fs/jfs/super.c:544 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 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] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3383 kmem_cache_zalloc include/linux/slab.h:689 [inline] ext4_init_io_end+0x25/0x120 fs/ext4/page-io.c:278 ext4_writepages+0xb55/0x2f40 fs/ext4/inode.c:2821 do_writepages+0x3ba/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x156/0x1160 fs/fs-writeback.c:1622 writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984 wb_writeback+0x494/0xd50 fs/fs-writeback.c:2089 wb_check_old_data_flush fs/fs-writeback.c:2189 [inline] wb_do_writeback fs/fs-writeback.c:2242 [inline] wb_workfn+0xb68/0xee0 fs/fs-writeback.c:2270 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 Memory state around the buggy address: ffff888072b1bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888072b1bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888072b1c000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ^ ffff888072b1c080: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff888072b1c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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