================================================================== 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+0x7c4/0x830 drivers/ptp/ptp_chardev.c:547 Read of size 4 at addr ffff8880142a5004 by task syz-executor.3/21057 CPU: 3 PID: 21057 Comm: syz-executor.3 Not tainted 6.6.0-syzkaller-15477-g34f763262743 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 queue_cnt drivers/ptp/ptp_private.h:89 [inline] ptp_read+0x7c4/0x830 drivers/ptp/ptp_chardev.c:547 posix_clock_read+0x138/0x1b0 kernel/time/posix-clock.c:51 vfs_read+0x1ce/0x8f0 fs/read_write.c:468 ksys_read+0x12f/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fca5667cae9 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:00007fca551fe0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fca5679bf80 RCX: 00007fca5667cae9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fca566c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fca5679bf80 R15: 00007ffdfcbf1678 Allocated by task 21057: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa3/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] ptp_open+0xe3/0x4f0 drivers/ptp/ptp_chardev.c:112 posix_clock_open+0x17e/0x240 kernel/time/posix-clock.c:134 chrdev_open+0x26d/0x6e0 fs/char_dev.c:414 do_dentry_open+0x8d4/0x18d0 fs/open.c:948 do_open fs/namei.c:3622 [inline] path_openat+0x1d4e/0x2c40 fs/namei.c:3779 do_filp_open+0x1de/0x430 fs/namei.c:3809 do_sys_openat2+0x176/0x1e0 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+0x175/0x210 fs/open.c:1466 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Freed by task 21072: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x138/0x190 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] __cache_free mm/slab.c:3370 [inline] __do_kmem_cache_free mm/slab.c:3557 [inline] __kmem_cache_free+0xcc/0x3d0 mm/slab.c:3564 ptp_release+0x204/0x2b0 drivers/ptp/ptp_chardev.c:150 ptp_read+0xf6/0x830 drivers/ptp/ptp_chardev.c:589 posix_clock_read+0x138/0x1b0 kernel/time/posix-clock.c:51 vfs_read+0x1ce/0x8f0 fs/read_write.c:468 ksys_read+0x12f/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff8880142a4000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 4100 bytes inside of freed 8192-byte region [ffff8880142a4000, ffff8880142a6000) The buggy address belongs to the physical page: page:ffffea000050a900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x142a4 head:ffffea000050a900 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0x1() raw: 00fff00000000840 ffff888013040a00 ffffea000086dc10 ffff888013041b50 raw: 0000000000000000 ffff8880142a4000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 21057, tgid 21055 (syz-executor.3), ts 857341224159, free_ts 857298475363 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1544 [inline] get_page_from_freelist+0xa25/0x36c0 mm/page_alloc.c:3312 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4568 __alloc_pages_node include/linux/gfp.h:238 [inline] kmem_getpages mm/slab.c:1356 [inline] cache_grow_begin+0x99/0x3a0 mm/slab.c:2550 cache_alloc_refill+0x294/0x3a0 mm/slab.c:2923 ____cache_alloc mm/slab.c:2999 [inline] ____cache_alloc mm/slab.c:2982 [inline] __do_cache_alloc mm/slab.c:3182 [inline] slab_alloc_node mm/slab.c:3230 [inline] __kmem_cache_alloc_node+0x3ba/0x460 mm/slab.c:3521 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] ptp_open+0xe3/0x4f0 drivers/ptp/ptp_chardev.c:112 posix_clock_open+0x17e/0x240 kernel/time/posix-clock.c:134 chrdev_open+0x26d/0x6e0 fs/char_dev.c:414 do_dentry_open+0x8d4/0x18d0 fs/open.c:948 do_open fs/namei.c:3622 [inline] path_openat+0x1d4e/0x2c40 fs/namei.c:3779 do_filp_open+0x1de/0x430 fs/namei.c:3809 do_sys_openat2+0x176/0x1e0 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+0x175/0x210 fs/open.c:1466 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3f/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+0x4f8/0xa90 mm/page_alloc.c:2347 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2487 slab_destroy mm/slab.c:1608 [inline] slabs_destroy+0x85/0xc0 mm/slab.c:1628 cache_flusharray mm/slab.c:3341 [inline] ___cache_free+0x2b7/0x420 mm/slab.c:3404 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4c/0x1b0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slab.c:3237 [inline] slab_alloc mm/slab.c:3246 [inline] __kmem_cache_alloc_lru mm/slab.c:3423 [inline] kmem_cache_alloc+0x159/0x3f0 mm/slab.c:3432 mt_alloc_one lib/maple_tree.c:160 [inline] mas_alloc_nodes+0x182/0x830 lib/maple_tree.c:1265 mas_node_count_gfp+0x105/0x130 lib/maple_tree.c:1345 mas_preallocate+0x2d7/0xda0 lib/maple_tree.c:5520 vma_iter_prealloc mm/internal.h:1149 [inline] vma_expand+0x64b/0x12c0 mm/mmap.c:658 mmap_region+0x1ba9/0x2820 mm/mmap.c:2822 do_mmap+0x893/0xef0 mm/mmap.c:1379 vm_mmap_pgoff+0x1a8/0x3b0 mm/util.c:546 ksys_mmap_pgoff+0x422/0x5b0 mm/mmap.c:1425 Memory state around the buggy address: ffff8880142a4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880142a4f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880142a5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880142a5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880142a5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================