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BUG: KASAN: slab-out-of-bounds in udf_writepages+0x389/0x4e0
Write of size 4096 at addr ffff88803178bc00 by task syz.4.1580/10216

CPU: 1 UID: 0 PID: 10216 Comm: syz.4.1580 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 kasan_check_range+0x2b0/0x2c0
 __asan_memcpy+0x40/0x70
 udf_writepages+0x389/0x4e0
 do_writepages+0x32e/0x550
 file_write_and_wait_range+0x23e/0x340
 __generic_file_fsync+0x6e/0x1b0
 generic_file_fsync+0x6c/0xe0
 udf_file_write_iter+0x54e/0x6c0
 iter_file_splice_write+0x975/0x10e0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x5a8/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f02c538eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f02c6184038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f02c55d5fa0 RCX: 00007f02c538eba9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000006
RBP: 00007f02c5411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000003ffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f02c55d6038 R14: 00007f02c55d5fa0 R15: 00007ffeecdf38f8
 </TASK>

Allocated by task 10216:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 udf_new_inode+0x313/0xd50
 udf_create+0x23/0xf0
 path_openat+0x14f4/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_creat+0x8f/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803178bc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 allocated 336-byte region [ffff88803178bc00, ffff88803178bd50)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31788
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000c5e201 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5858, tgid 5858 (syz-executor), ts 67387518461, free_ts 0
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1420
 __kmalloc_noprof+0x305/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 add_v4_addrs+0x8b3/0xbd0
 addrconf_init_auto_addrs+0x6da/0xa30
 addrconf_notify+0xacc/0x1010
 notifier_call_chain+0x1b6/0x3e0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88803178bc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88803178bc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88803178bd00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff88803178bd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803178be00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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