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BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1516
Read of size 1 at addr ffff88810c8a9900 by task syz.4.578/3339

CPU: 1 PID: 3339 Comm: syz.4.578 Not tainted 5.10.226-syzkaller-00709-ge5e5644ea27f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1516
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1700
 __ext4_find_entry+0x2b0/0x1990 fs/ext4/namei.c:1589
 ext4_lookup_entry fs/ext4/namei.c:1744 [inline]
 ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1812
 __lookup_hash+0x143/0x290 fs/namei.c:1541
 filename_create+0x202/0x750 fs/namei.c:3608
 user_path_create fs/namei.c:3665 [inline]
 do_mkdirat+0xcc/0x2c0 fs/namei.c:3805
 __do_sys_mkdirat fs/namei.c:3823 [inline]
 __se_sys_mkdirat fs/namei.c:3821 [inline]
 __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3821
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f0f09f4b897
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007f0f08b83e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0f08b83ef0 RCX: 00007f0f09f4b897
RDX: 00000000000001ff RSI: 0000000020000100 RDI: 00000000ffffff9c
RBP: 0000000020000040 R08: 0000000020000000 R09: 0000000000000000
R10: 0000000020000040 R11: 0000000000000246 R12: 0000000020000100
R13: 00007f0f08b83eb0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 3067:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 __kasan_slab_alloc+0xb1/0xe0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x61/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x168/0x2e0 mm/slub.c:2960
 kmem_cache_alloc_node include/linux/slab.h:423 [inline]
 __alloc_skb+0x80/0x510 net/core/skbuff.c:200
 alloc_skb include/linux/skbuff.h:1126 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 netlink_ack+0x33c/0xb30 net/netlink/af_netlink.c:2434
 netlink_rcv_skb+0x24c/0x410 net/netlink/af_netlink.c:2505
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5625
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x8df/0xac0 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0xa46/0xd00 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 __sys_sendto+0x545/0x700 net/socket.c:2006
 __do_sys_sendto net/socket.c:2018 [inline]
 __se_sys_sendto net/socket.c:2014 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2014
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 3067:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x121/0x160 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:1595 [inline]
 slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0xa9/0x1e0 mm/slub.c:3219
 kfree_skbmem+0x104/0x170
 __kfree_skb net/core/skbuff.c:695 [inline]
 consume_skb+0xb4/0x250 net/core/skbuff.c:851
 skb_free_datagram+0x28/0xe0 net/core/datagram.c:325
 netlink_recvmsg+0x5ef/0x11b0 net/netlink/af_netlink.c:1995
 sock_recvmsg_nosec net/socket.c:905 [inline]
 sock_recvmsg net/socket.c:923 [inline]
 __sys_recvfrom+0x432/0x5d0 net/socket.c:2063
 __do_sys_recvfrom net/socket.c:2081 [inline]
 __se_sys_recvfrom net/socket.c:2077 [inline]
 __x64_sys_recvfrom+0xe5/0x100 net/socket.c:2077
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff88810c8a98c0
 which belongs to the cache skbuff_head_cache of size 248
The buggy address is located 64 bytes inside of
 248-byte region [ffff88810c8a98c0, ffff88810c8a99b8)
The buggy address belongs to the page:
page:ffffea0004322a40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10c8a9
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff888107d9dc80
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 3067, ts 211614107803, free_ts 211610415435
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x80/0x400 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x302/0x4b0 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1b9/0x2e0 mm/slub.c:2960
 kmem_cache_alloc_node include/linux/slab.h:423 [inline]
 __alloc_skb+0x80/0x510 net/core/skbuff.c:200
 alloc_skb include/linux/skbuff.h:1126 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 rtmsg_ifinfo_build_skb+0x7f/0x180 net/core/rtnetlink.c:3841
 rtmsg_ifinfo_event net/core/rtnetlink.c:3877 [inline]
 rtnetlink_event+0xf3/0x1b0 net/core/rtnetlink.c:5658
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:410
 call_netdevice_notifiers_info net/core/dev.c:2054 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2066 [inline]
 call_netdevice_notifiers net/core/dev.c:2080 [inline]
 dev_set_mac_address+0x325/0x470 net/core/dev.c:8775
 dev_set_mac_address_user+0x31/0x50 net/core/dev.c:8789
 do_setlink+0x72e/0x3c30 net/core/rtnetlink.c:2684
 __rtnl_newlink net/core/rtnetlink.c:3407 [inline]
 rtnl_newlink+0x15f0/0x2000 net/core/rtnetlink.c:3527
 rtnetlink_rcv_msg+0x955/0xc50 net/core/rtnetlink.c:5607
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_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page+0x9e/0x370 mm/page_alloc.c:5407
 __free_pages+0x67/0xc0 mm/page_alloc.c:5418
 __vunmap+0x7bc/0x8f0 mm/vmalloc.c:2301
 __vfree mm/vmalloc.c:2349 [inline]
 vfree+0x5c/0x80 mm/vmalloc.c:2380
 module_memfree+0x17/0x30 kernel/module.c:2205
 bpf_jit_free_exec+0x15/0x20 kernel/bpf/core.c:866
 bpf_jit_binary_free+0x4e/0x2b0 kernel/bpf/core.c:915
 bpf_jit_free+0x7c/0x1e0 kernel/bpf/core.c:928
 bpf_prog_free_deferred+0x4ba/0x550 kernel/bpf/core.c:2212
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
 ffff88810c8a9800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
 ffff88810c8a9880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff88810c8a9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88810c8a9980: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
 ffff88810c8a9a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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