loop4: detected capacity change from 0 to 32768 ================================================================== BUG: KASAN: use-after-free in dtMoveEntry fs/jfs/jfs_dtree.c:3922 [inline] BUG: KASAN: use-after-free in dtSplitPage+0x1a21/0x3160 fs/jfs/jfs_dtree.c:1561 Write of size 1 at addr ffff888079d68000 by task syz.4.577/7416 CPU: 0 PID: 7416 Comm: syz.4.577 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 dtMoveEntry fs/jfs/jfs_dtree.c:3922 [inline] dtSplitPage+0x1a21/0x3160 fs/jfs/jfs_dtree.c:1561 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x106f/0x57e0 fs/jfs/jfs_dtree.c:871 jfs_symlink+0x8bb/0xfd0 fs/jfs/namei.c:1019 vfs_symlink+0x245/0x3d0 fs/namei.c:4522 do_symlinkat+0x1b6/0x400 fs/namei.c:4551 __do_sys_symlinkat fs/namei.c:4568 [inline] __se_sys_symlinkat fs/namei.c:4565 [inline] __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4565 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: 0033:0x7f17cd99e1d9 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:00007f17cbbf6028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f17cdc25fa0 RCX: 00007f17cd99e1d9 RDX: 0000200000007f00 RSI: ffffffffffffff9c RDI: 0000200000007dc0 RBP: 00007f17cda35888 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f17cdc26038 R14: 00007f17cdc25fa0 R15: 00007ffcb297bfb8 Allocated by task 35: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node_track_caller+0xb0/0x240 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x226/0x7d0 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1303 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x24f/0xa80 drivers/net/netdevsim/dev.c:851 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 35: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3700 skb_free_head net/core/skbuff.c:762 [inline] skb_release_data+0x5e9/0x7e0 net/core/skbuff.c:791 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] consume_skb+0xa2/0x100 net/core/skbuff.c:1038 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x71f/0xa80 drivers/net/netdevsim/dev.c:851 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888079d68000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff888079d68000, ffff888079d69000) The buggy address belongs to the physical page: page:ffffea0001e75a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79d68 head:ffffea0001e75a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888018442140 raw: 0000000000000000 0000000000040004 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 35, tgid 35 (kworker/u4:2), ts 359055022329, free_ts 332821109298 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0xa0/0x240 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x226/0x7d0 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1303 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x24f/0xa80 drivers/net/netdevsim/dev.c:851 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 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/0x490 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+0x18b/0x2f0 mm/slub.c:3383 getname_flags+0xb7/0x500 fs/namei.c:139 user_path_at_empty+0x28/0x60 fs/namei.c:2955 user_path_at include/linux/namei.h:57 [inline] ksys_umount fs/namespace.c:1829 [inline] __do_sys_umount fs/namespace.c:1837 [inline] __se_sys_umount fs/namespace.c:1835 [inline] __x64_sys_umount+0xf9/0x170 fs/namespace.c:1835 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 Memory state around the buggy address: ffff888079d67f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888079d67f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888079d68000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888079d68080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888079d68100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================