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BUG: KASAN: slab-out-of-bounds in ecryptfs_write_tag_70_packet+0x1241/0x12e0 fs/ecryptfs/keystore.c:742
Read of size 4 at addr ffff88803f835e98 by task syz.0.0/5324

CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 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_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 ecryptfs_write_tag_70_packet+0x1241/0x12e0 fs/ecryptfs/keystore.c:742
 ecryptfs_encrypt_filename fs/ecryptfs/crypto.c:1378 [inline]
 ecryptfs_encrypt_and_encode_filename+0x576/0x1580 fs/ecryptfs/crypto.c:1789
 ecryptfs_lookup+0x20e/0x780 fs/ecryptfs/inode.c:402
 __lookup_slow+0x1fb/0x2f0 fs/namei.c:1919
 lookup_slow+0x53/0x70 fs/namei.c:1936
 walk_component fs/namei.c:2282 [inline]
 lookup_last fs/namei.c:2789 [inline]
 path_lookupat+0x3f5/0x8c0 fs/namei.c:2813
 filename_lookup+0x265/0x5d0 fs/namei.c:2842
 do_faccessat+0x632/0xdc0 fs/open.c:488
 __do_sys_faccessat fs/open.c:536 [inline]
 __se_sys_faccessat fs/open.c:534 [inline]
 __x64_sys_faccessat+0x7c/0x90 fs/open.c:534
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f701019e159
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:00007f7011016fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000010d
RAX: ffffffffffffffda RBX: 00007f7010425fa0 RCX: 00007f701019e159
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f701023506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7010426038 R14: 00007f7010425fa0 R15: 00007ffd188576f8
 </TASK>

Allocated by task 5324:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5414 [inline]
 __kmalloc_noprof+0x36b/0x720 mm/slub.c:5439
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 user_preparse+0x9e/0x160 security/keys/user_defined.c:67
 __key_create_or_update+0x3a9/0xa80 security/keys/key.c:857
 key_create_or_update+0x42/0x60 security/keys/key.c:1021
 __do_sys_add_key security/keys/keyctl.c:134 [inline]
 __se_sys_add_key+0x349/0x420 security/keys/keyctl.c:74
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803f835c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 270 bytes to the right of
 allocated 394-byte region [ffff88803f835c00, ffff88803f835d8a)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3f834
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b041c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b041c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 04fff00000000001 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 5284, tgid 5284 (syz-executor), ts 92301737136
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7417
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x39b/0x600 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 mca_alloc net/ipv6/mcast.c:890 [inline]
 __ipv6_dev_mc_inc+0x447/0xaf0 net/ipv6/mcast.c:981
 ipv6_add_dev+0xe45/0x13a0 net/ipv6/addrconf.c:475
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3686
 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
 call_netdevice_notifiers net/core/dev.c:2327 [inline]
 register_netdevice+0x18a4/0x1eb0 net/core/dev.c:11541
 cfg80211_register_netdevice+0x138/0x2d0 net/wireless/core.c:1719
 ieee80211_if_add+0x108d/0x1600 net/mac80211/iface.c:2430
 ieee80211_register_hw+0x3ef7/0x4b00 net/mac80211/main.c:1647
 mac80211_hwsim_new_radio+0x3258/0x56b0 drivers/net/wireless/virtual/mac80211_hwsim_main.c:6143
page last free pid 5284 tgid 5284 ts 91943443166 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
 __slab_free+0x274/0x2c0 mm/slub.c:5823
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 __kmalloc_cache_noprof+0x29f/0x600 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 inet_alloc_ifa net/ipv4/devinet.c:212 [inline]
 inet_rtm_to_ifa net/ipv4/devinet.c:904 [inline]
 inet_rtm_newaddr+0x613/0x19f0 net/ipv4/devinet.c:980
 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7137
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2575
 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1364
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
 __sock_sendmsg net/socket.c:815 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2281
 __do_sys_sendto net/socket.c:2288 [inline]
 __se_sys_sendto net/socket.c:2284 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2284
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88803f835d80: 00 02 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803f835e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88803f835e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff88803f835f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803f835f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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