================================================================== 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 ffff88805a6f5004 by task syz-executor.4/1853 CPU: 0 PID: 1853 Comm: syz-executor.4 Not tainted 6.6.0-syzkaller-15494-g6bc986ab839c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __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: 0033:0x7f918167cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007f91824c50c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f918179bf80 RCX: 00007f918167cae9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f91816c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f918179bf80 R15: 00007ffd7a6f23f8 Allocated by task 1853: 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 1864: 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 ffff88805a6f4000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 4100 bytes inside of freed 8192-byte region [ffff88805a6f4000, ffff88805a6f6000) The buggy address belongs to the physical page: page:ffffea000169bc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a6f0 head:ffffea000169bc00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012c42280 0000000000000000 dead000000000001 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 5078, tgid 5078 (syz-executor.4), ts 58648076754, free_ts 14356666625 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+0xa7/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kvmalloc_node+0x72/0x180 mm/util.c:607 kvmalloc include/linux/slab.h:738 [inline] kvmalloc_array include/linux/slab.h:756 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:471 [inline] ptr_ring_init include/linux/ptr_ring.h:489 [inline] skb_array_init include/linux/skb_array.h:182 [inline] pfifo_fast_init+0x389/0x6d0 net/sched/sch_generic.c:858 qdisc_create_dflt+0x135/0x480 net/sched/sch_generic.c:1004 attach_one_default_qdisc net/sched/sch_generic.c:1160 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2538 [inline] attach_default_qdiscs net/sched/sch_generic.c:1178 [inline] dev_activate+0x3b8/0x1200 net/sched/sch_generic.c:1237 __dev_open+0x34c/0x440 net/core/dev.c:1454 __dev_change_flags+0x1df/0x6e0 net/core/dev.c:8603 dev_change_flags+0x8b/0x1a0 net/core/dev.c:8675 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 free_contig_range+0x9e/0x150 mm/page_alloc.c:6536 destroy_args+0x8a/0x880 mm/debug_vm_pgtable.c:1028 debug_vm_pgtable+0x4ba/0x540 mm/debug_vm_pgtable.c:1408 do_one_initcall+0x234/0x800 init/main.c:1236 do_initcall_level+0x157/0x210 init/main.c:1298 do_initcalls+0x3f/0x80 init/main.c:1314 kernel_init_freeable+0x429/0x5c0 init/main.c:1551 kernel_init+0x1d/0x2a0 init/main.c:1441 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Memory state around the buggy address: ffff88805a6f4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a6f4f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a6f5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a6f5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a6f5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================