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BUG: KASAN: slab-use-after-free in ecryptfs_write_tag_70_packet+0x117b/0x1410 fs/ecryptfs/keystore.c:742
Read of size 4 at addr ffff888037bcee98 by task syz.3.10/5976

CPU: 3 UID: 0 PID: 5976 Comm: syz.3.10 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 ecryptfs_write_tag_70_packet+0x117b/0x1410 fs/ecryptfs/keystore.c:742
 ecryptfs_encrypt_filename fs/ecryptfs/crypto.c:1378 [inline]
 ecryptfs_encrypt_and_encode_filename+0x428/0xa60 fs/ecryptfs/crypto.c:1789
 ecryptfs_lookup+0x1f7/0x830 fs/ecryptfs/inode.c:402
 lookup_open+0xb29/0x19e0 fs/namei.c:4536
 open_last_lookups fs/namei.c:4774 [inline]
 path_openat+0xe75/0x23f0 fs/namei.c:5013
 do_file_open+0x20e/0x430 fs/namei.c:5045
 do_sys_openat2+0x163/0x1d0 fs/open.c:1442
 do_sys_open fs/open.c:1448 [inline]
 __do_sys_openat fs/open.c:1464 [inline]
 __se_sys_openat fs/open.c:1459 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1459
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5552f9fb19
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:00007f5553e5d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5553225fa0 RCX: 00007f5552f9fb19
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000008
RBP: 00007f5553037b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000090 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5553226038 R14: 00007f5553225fa0 R15: 00007fffba21a358
 </TASK>

Allocated by task 5976:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5531 [inline]
 __kvmalloc_node_noprof+0x35b/0x9b0 mm/slub.c:7136
 __do_sys_add_key+0x244/0x460 security/keys/keyctl.c:116
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5976:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6923
 __do_sys_add_key+0x370/0x460 security/keys/keyctl.c:147
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888037bcee00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 152 bytes inside of
 freed 256-byte region [ffff888037bcee00, ffff888037bcef00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x37bce
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801d442b40 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d442b40 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5965, tgid 5964 (syz.3.7), ts 41697714994
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x112f/0x3640 mm/page_alloc.c:3940
 __alloc_frozen_pages_noprof+0x2ad/0x31e0 mm/page_alloc.c:5464
 alloc_slab_page mm/slub.c:3384 [inline]
 allocate_slab mm/slub.c:3499 [inline]
 new_slab+0xb1/0x6d0 mm/slub.c:3550
 refill_objects+0xe3/0x410 mm/slub.c:7539
 refill_sheaf mm/slub.c:2917 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
 alloc_from_pcs mm/slub.c:4887 [inline]
 slab_alloc_node mm/slub.c:5021 [inline]
 __do_kmalloc_node mm/slub.c:5530 [inline]
 __kvmalloc_node_noprof+0x7b6/0x9b0 mm/slub.c:7136
 bpf_jit_binary_pack_alloc+0xd2/0x2b0 kernel/bpf/core.c:1223
 bpf_int_jit_compile+0x526/0x1a40 arch/x86/net/bpf_jit_comp.c:4941
 bpf_prog_jit_compile kernel/bpf/core.c:2704 [inline]
 __bpf_prog_select_runtime+0x8d1/0xbf0 kernel/bpf/core.c:2759
 bpf_check+0x37c0/0xa0f0 kernel/bpf/verifier.c:24286
 bpf_prog_load+0x1baf/0x2b20 kernel/bpf/syscall.c:3172
 __sys_bpf+0x146f/0x4b60 kernel/bpf/syscall.c:6460
 __do_sys_bpf kernel/bpf/syscall.c:6582 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6579 [inline]
 __x64_sys_bpf+0xce/0x140 kernel/bpf/syscall.c:6579
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5955 tgid 5954 ts 41527412279 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2957
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4720 [inline]
 slab_alloc_node mm/slub.c:5033 [inline]
 __kmalloc_cache_noprof+0x278/0x6d0 mm/slub.c:5676
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 kobject_uevent_env+0x263/0x18b0 lib/kobject_uevent.c:543
 device_del+0x605/0x9b0 drivers/base/core.c:3985
 unregister_netdevice_many_notify+0x1255/0x1e00 net/core/dev.c:12777
 rtnl_newlink_create net/core/rtnetlink.c:4032 [inline]
 __rtnl_newlink net/core/rtnetlink.c:4135 [inline]
 rtnl_newlink+0x1c09/0x2620 net/core/rtnetlink.c:4252
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7169
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2584
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x668/0x950 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x9ac/0x10c0 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec net/socket.c:800 [inline]
 __sock_sendmsg net/socket.c:818 [inline]
 ____sys_sendmsg+0xa99/0xc30 net/socket.c:2715
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2769
 __sys_sendmsg+0x160/0x210 net/socket.c:2801

Memory state around the buggy address:
 ffff888037bced80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888037bcee00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888037bcee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888037bcef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888037bcef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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