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BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1221
Read of size 1 at addr ffff888119431535 by task syz-executor/475

CPU: 0 PID: 475 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1221
 ext4_dx_readdir fs/ext4/dir.c:601 [inline]
 ext4_readdir+0x2b45/0x39b0 fs/ext4/dir.c:145
 iterate_dir+0x260/0x570 fs/readdir.c:-1
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0xe5/0x240 fs/readdir.c:354
 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f785421b873
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 a2 3e f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8
RSP: 002b:00007ffec3e8e588 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 000055556fa754e0 RCX: 00007f785421b873
RDX: 0000000000008000 RSI: 000055556fa754e0 RDI: 0000000000000005
RBP: 000055556fa754b4 R08: 0000000000028b61 R09: 0000000000000000
R10: 00007f7854379ca0 R11: 0000000000000293 R12: ffffffffffffffa8
R13: 0000000000000010 R14: 000055556fa754b0 R15: 00007ffec3e90830

Allocated by task 0:
(stack is not available)

Freed by task 9:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1600 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626
 slab_free mm/slub.c:3208 [inline]
 kfree+0xc0/0x270 mm/slub.c:4196
 skb_free_head net/core/skbuff.c:606 [inline]
 skb_release_data+0x532/0x670 net/core/skbuff.c:626
 skb_release_all net/core/skbuff.c:680 [inline]
 __kfree_skb net/core/skbuff.c:694 [inline]
 consume_skb+0xab/0x1f0 net/core/skbuff.c:851
 netlink_broadcast_filtered+0x117d/0x1270 net/netlink/af_netlink.c:1530
 netlink_broadcast net/netlink/af_netlink.c:1552 [inline]
 nlmsg_multicast include/net/netlink.h:1033 [inline]
 nlmsg_notify+0xed/0x1b0 net/netlink/af_netlink.c:2546
 rtnl_notify net/core/rtnetlink.c:737 [inline]
 rtmsg_ifinfo_send net/core/rtnetlink.c:3868 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:3883 [inline]
 rtmsg_ifinfo+0xea/0x130 net/core/rtnetlink.c:3889
 netdev_state_change+0x185/0x210 net/core/dev.c:1486
 linkwatch_do_dev+0x102/0x140 net/core/link_watch.c:167
 __linkwatch_run_queue+0x4a9/0x7b0 net/core/link_watch.c:213
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:252
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 process_scheduled_works kernel/workqueue.c:2363 [inline]
 worker_thread+0xd56/0x13b0 kernel/workqueue.c:2449
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff888119431000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1333 bytes inside of
 2048-byte region [ffff888119431000, ffff888119431800)
The buggy address belongs to the page:
page:ffffea0004650c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x119430
head:ffffea0004650c00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042d80
raw: 0000000000000000 0000000000080008 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 0x1d28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 9, ts 45970397633, free_ts 45953152718
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 __kmalloc_track_caller+0x1ef/0x320 mm/slub.c:4541
 __kmalloc_reserve net/core/skbuff.c:144 [inline]
 pskb_expand_head+0x123/0x1110 net/core/skbuff.c:1653
 netlink_trim+0x193/0x230 net/netlink/af_netlink.c:1295
 netlink_broadcast_filtered+0x78/0x1270 net/netlink/af_netlink.c:1507
 netlink_broadcast net/netlink/af_netlink.c:1552 [inline]
 nlmsg_multicast include/net/netlink.h:1033 [inline]
 nlmsg_notify+0xed/0x1b0 net/netlink/af_netlink.c:2546
 rtnl_notify net/core/rtnetlink.c:737 [inline]
 rtmsg_ifinfo_send net/core/rtnetlink.c:3868 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:3883 [inline]
 rtmsg_ifinfo+0xea/0x130 net/core/rtnetlink.c:3889
 netdev_state_change+0x185/0x210 net/core/dev.c:1486
 linkwatch_do_dev+0x102/0x140 net/core/link_watch.c:167
 __linkwatch_run_queue+0x4a9/0x7b0 net/core/link_watch.c:213
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:252
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 __free_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629
 free_the_page mm/page_alloc.c:5431 [inline]
 __free_pages+0xdd/0x380 mm/page_alloc.c:5440
 __free_slab+0xcf/0x190 mm/slub.c:1899
 free_slab mm/slub.c:1914 [inline]
 discard_slab+0x29/0x40 mm/slub.c:1920
 __slab_free+0x313/0x3a0 mm/slub.c:3136
 do_slab_free mm/slub.c:3196 [inline]
 ___cache_free+0x111/0x130 mm/slub.c:3215
 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580
 slab_alloc_node mm/slub.c:2952 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2965
 getname_flags+0xb9/0x500 fs/namei.c:141
 user_path_at_empty+0x2f/0x50 fs/namei.c:2748
 user_path_at include/linux/namei.h:60 [inline]
 vfs_statx+0xff/0x520 fs/stat.c:193
 vfs_fstatat fs/stat.c:215 [inline]
 __do_sys_newfstatat fs/stat.c:383 [inline]
 __se_sys_newfstatat+0xc6/0x340 fs/stat.c:377

Memory state around the buggy address:
 ffff888119431400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888119431480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888119431500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888119431580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888119431600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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