================================================================== 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 ffff888078735004 by task syz-executor304/5057 CPU: 1 PID: 5057 Comm: syz-executor304 Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #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+0x142/0x170 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: 0033:0x7f5438b16c39 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:00007f5438ad9238 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f5438ba0308 RCX: 00007f5438b16c39 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f5438ba0300 R08: 00007f5438ad96c0 R09: 00007f5438ad96c0 R10: 00007f5438ad96c0 R11: 0000000000000246 R12: 7074702f7665642f R13: 0000000000000000 R14: 00007fffeb9398a0 R15: 00007fffeb939988 </TASK> Allocated by task 5057: 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 5058: 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 ffff888078734000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 4100 bytes inside of freed 8192-byte region [ffff888078734000, ffff888078736000) The buggy address belongs to the physical page: page:ffffea0001e1cc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78730 head:ffffea0001e1cc00 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 dead000000000122 0000000000000000 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4964, tgid 4964 (sshd), ts 45894976160, free_ts 45769063688 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1544 [inline] get_page_from_freelist+0x339a/0x3530 mm/page_alloc.c:3312 __alloc_pages+0x255/0x670 mm/page_alloc.c:4568 alloc_pages_mpol+0x3de/0x640 mm/mempolicy.c:2133 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+0x21d/0x300 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa5/0x230 mm/slab_common.c:1027 kmalloc_reserve+0xf3/0x260 net/core/skbuff.c:582 __alloc_skb+0x1b1/0x420 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [inline] netlink_dump+0x206/0xcd0 net/netlink/af_netlink.c:2233 netlink_recvmsg+0x6b9/0x11d0 net/netlink/af_netlink.c:1992 sock_recvmsg_nosec net/socket.c:1044 [inline] sock_recvmsg net/socket.c:1066 [inline] ____sys_recvmsg+0x2a4/0x580 net/socket.c:2807 ___sys_recvmsg net/socket.c:2849 [inline] __sys_recvmsg+0x2f0/0x3d0 net/socket.c:2879 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1137 [inline] free_unref_page_prepare+0x92a/0xa50 mm/page_alloc.c:2347 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487 napi_frag_unref include/linux/skbuff.h:3450 [inline] skb_release_data+0x446/0x850 net/core/skbuff.c:986 skb_release_all net/core/skbuff.c:1058 [inline] napi_consume_skb+0x14d/0x200 net/core/skbuff.c:1366 skb_defer_free_flush net/core/dev.c:6654 [inline] net_rx_action+0x554/0x1010 net/core/dev.c:6714 __do_softirq+0x2bf/0x93a kernel/softirq.c:553 Memory state around the buggy address: ffff888078734f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078734f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078735000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078735080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078735100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================