Hello, syzbot found the following issue on:
HEAD commit: 6174f052 Add linux-next specific files for 20201127 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=12252073500000 kernel config: https://syzkaller.appspot.com/x/.config?x=79c69cf2521bef9c dashboard link: https://syzkaller.appspot.com/bug?extid=19e6dd9943972fa1c58a compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c3351d500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14c28809500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+19e6dd9943972fa1c...@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in strlcpy include/linux/string.h:355 [inline] BUG: KASAN: use-after-free in kernfs_path_from_node_locked+0x9b3/0xc80 fs/kernfs/dir.c:138 Write of size 1 at addr ffff8880235cd800 by task systemd-rfkill/8530 CPU: 1 PID: 8530 Comm: systemd-rfkill Not tainted 5.10.0-rc5-next-20201127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230 __kasan_report mm/kasan/report.c:396 [inline] kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413 check_memory_region_inline mm/kasan/generic.c:180 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:186 memcpy+0x39/0x60 mm/kasan/shadow.c:66 strlcpy include/linux/string.h:355 [inline] kernfs_path_from_node_locked+0x9b3/0xc80 fs/kernfs/dir.c:138 kernfs_path_from_node+0x3a/0x60 fs/kernfs/dir.c:217 kernfs_path include/linux/kernfs.h:542 [inline] cgroup_path include/linux/cgroup.h:661 [inline] get_mm_memcg_path+0xb2/0xf0 mm/mmap_lock.c:130 __mmap_lock_do_trace_start_locking+0x25/0x2d0 mm/mmap_lock.c:172 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:135 [inline] do_user_addr_fault+0x638/0xc50 arch/x86/mm/fault.c:1339 handle_page_fault arch/x86/mm/fault.c:1455 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1511 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580 RIP: 0033:0x7f42776d4798 Code: Unable to access opcode bytes at RIP 0x7f42776d476e. RSP: 002b:00007fff34baaf68 EFLAGS: 00010202 RAX: 00007f42776d4798 RBX: 00007f4278d7d9e0 RCX: 0000000000000000 RDX: 00000000ffffffff RSI: 0000000000000000 RDI: 00007f4277918088 RBP: 00007fff34bab070 R08: 0000000000000000 R09: 00007f4278723808 R10: 00007f4277912000 R11: 0000000000000012 R12: 00007f4277910a50 R13: 00007fff34baafb0 R14: 00007f4278d86040 R15: 0000000000000000 Allocated by task 9024: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:39 kasan_set_track mm/kasan/common.c:47 [inline] set_alloc_info mm/kasan/common.c:405 [inline] ____kasan_kmalloc mm/kasan/common.c:436 [inline] ____kasan_kmalloc.constprop.0+0xa0/0xd0 mm/kasan/common.c:408 kmalloc include/linux/slab.h:552 [inline] trace_mmap_lock_reg+0x196/0x550 mm/mmap_lock.c:58 tracepoint_add_func+0x304/0x990 kernel/tracepoint.c:257 tracepoint_probe_register_prio kernel/tracepoint.c:342 [inline] tracepoint_probe_register+0x9c/0xe0 kernel/tracepoint.c:362 trace_event_reg+0x28f/0x350 kernel/trace/trace_events.c:305 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline] perf_trace_event_init+0x549/0xa20 kernel/trace/trace_event_perf.c:204 perf_trace_init+0x176/0x240 kernel/trace/trace_event_perf.c:228 perf_tp_event_init+0xa2/0x120 kernel/events/core.c:9590 perf_try_init_event+0x12a/0x560 kernel/events/core.c:11058 perf_init_event kernel/events/core.c:11110 [inline] perf_event_alloc.part.0+0xe3b/0x38e0 kernel/events/core.c:11388 perf_event_alloc kernel/events/core.c:11767 [inline] __do_sys_perf_event_open+0x72c/0x2cb0 kernel/events/core.c:11883 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 9024: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:39 kasan_set_track+0x1c/0x30 mm/kasan/common.c:47 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:358 ____kasan_slab_free.part.0+0xe1/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:187 [inline] slab_free_hook mm/slub.c:1548 [inline] slab_free_freelist_hook+0x82/0x1d0 mm/slub.c:1586 slab_free mm/slub.c:3157 [inline] kfree+0xe5/0x5c0 mm/slub.c:4156 trace_mmap_lock_unreg+0xba/0x160 mm/mmap_lock.c:94 tracepoint_remove_func kernel/tracepoint.c:306 [inline] tracepoint_probe_unregister+0x5b6/0x890 kernel/tracepoint.c:382 trace_event_reg+0x181/0x350 kernel/trace/trace_events.c:309 perf_trace_event_unreg.isra.0+0xac/0x250 kernel/trace/trace_event_perf.c:162 perf_trace_destroy+0xb5/0xf0 kernel/trace/trace_event_perf.c:243 _free_event+0x2ee/0x1300 kernel/events/core.c:4840 put_event kernel/events/core.c:4934 [inline] perf_event_release_kernel+0xa24/0xe00 kernel/events/core.c:5049 perf_release+0x33/0x40 kernel/events/core.c:5059 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x1f0/0x200 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x36/0x260 kernel/entry/common.c:277 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880235cd800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of 1024-byte region [ffff8880235cd800, ffff8880235cdc00) The buggy address belongs to the page: page:0000000010e16530 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x235cc head:0000000010e16530 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010041140 raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880235cd700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880235cd780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880235cd800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880235cd880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880235cd900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. 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