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BUG: KASAN: slab-use-after-free in queue_cnt drivers/ptp/ptp_private.h:89 [inline]
BUG: KASAN: slab-use-after-free in ptp_read+0x5e4/0x820 drivers/ptp/ptp_chardev.c:547
Read of size 4 at addr ffff8880196cd004 by task syz-executor184/5050

CPU: 1 PID: 5050 Comm: syz-executor184 Not tainted 6.6.0-syzkaller-05843-g89ed67ef126c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x175/0x1b0 mm/kasan/report.c:588
 queue_cnt drivers/ptp/ptp_private.h:89 [inline]
 ptp_read+0x5e4/0x820 drivers/ptp/ptp_chardev.c:547
 posix_clock_read+0x12f/0x190 kernel/time/posix-clock.c:51
 vfs_read+0x289/0xb00 fs/read_write.c:468
 ksys_read+0x1a0/0x2c0 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f6038e4cc39
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6038e0f238 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f6038ed6308 RCX: 00007f6038e4cc39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f6038ed6300 R08: 00007f6038e0f6c0 R09: 00007f6038e0f6c0
R10: 00007f6038e0f6c0 R11: 0000000000000246 R12: 7074702f7665642f
R13: 0000000000000000 R14: 00007ffef2fb9890 R15: 00007ffef2fb9978
 </TASK>

Allocated by task 5050:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 ptp_open+0xd9/0x430 drivers/ptp/ptp_chardev.c:112
 posix_clock_open+0x155/0x1f0 kernel/time/posix-clock.c:134
 chrdev_open+0x5ab/0x630 fs/char_dev.c:414
 do_dentry_open+0x8fd/0x1590 fs/open.c:948
 do_open fs/namei.c:3622 [inline]
 path_openat+0x2845/0x3280 fs/namei.c:3779
 do_filp_open+0x234/0x490 fs/namei.c:3809
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1440
 do_sys_open fs/open.c:1455 [inline]
 __do_sys_openat fs/open.c:1471 [inline]
 __se_sys_openat fs/open.c:1466 [inline]
 __x64_sys_openat+0x247/0x290 fs/open.c:1466
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Freed by task 5051:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0x263/0x3a0 mm/slub.c:3822
 ptp_release+0x1ce/0x1e0 drivers/ptp/ptp_chardev.c:150
 ptp_read+0x17f/0x820 drivers/ptp/ptp_chardev.c:589
 posix_clock_read+0x12f/0x190 kernel/time/posix-clock.c:51
 vfs_read+0x289/0xb00 fs/read_write.c:468
 ksys_read+0x1a0/0x2c0 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

The buggy address belongs to the object at ffff8880196cc000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4100 bytes inside of
 freed 8192-byte region [ffff8880196cc000, ffff8880196ce000)

The buggy address belongs to the physical page:
page:ffffea000065b200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x196c8
head:ffffea000065b200 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888012c42280 ffffea0001eb2200 dead000000000002
raw: 0000000000000000 0000000080020002 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 4049480476, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1536
 prep_new_page mm/page_alloc.c:1543 [inline]
 get_page_from_freelist+0x31db/0x3360 mm/page_alloc.c:3170
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4426
 alloc_page_interleave+0x22/0x1d0 mm/mempolicy.c:2136
 alloc_slab_page+0x6a/0x160 mm/slub.c:1870
 allocate_slab mm/slub.c:2017 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2070
 ___slab_alloc+0xc85/0x1310 mm/slub.c:3223
 __slab_alloc mm/slub.c:3322 [inline]
 __slab_alloc_node mm/slub.c:3375 [inline]
 slab_alloc_node mm/slub.c:3468 [inline]
 __kmem_cache_alloc_node+0x19d/0x270 mm/slub.c:3517
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 mr_table_alloc+0x65/0x250 net/ipv4/ipmr_base.c:41
 ipmr_new_table net/ipv4/ipmr.c:409 [inline]
 ipmr_rules_init net/ipv4/ipmr.c:250 [inline]
 ipmr_net_init+0x24b/0x3c0 net/ipv4/ipmr.c:3085
 ops_init+0x351/0x600 net/core/net_namespace.c:136
 __register_pernet_operations net/core/net_namespace.c:1165 [inline]
 register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1234
 register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1275
 ip_mr_init+0x39/0x160 net/ipv4/ipmr.c:3148
 inet_init+0x307/0x3d0 net/ipv4/af_inet.c:2047
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880196ccf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880196ccf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880196cd000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880196cd080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880196cd100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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