KASAN: slab-out-of-bounds Read in perf_event_fd_array_release
From: syzbot <hidden>
Date: 2018-01-10 12:59:04
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Hello, syzkaller hit the following crash on b4464bcab38d3f7fe995a7cb960eeac6889bec08 git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master compiler: gcc (GCC) 7.1.1 20170620 .config is attached Raw console output is attached. C reproducer is attached syzkaller reproducer is attached. See https://goo.gl/kgGztJ for information about syzkaller reproducers IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+6c15e9744f75f2364773@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer. audit: type=1400 audit(1515566962.610:11): avc: denied { map_read map_write } for pid=3488 comm="syzkaller000829" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 ================================================================== BUG: KASAN: slab-out-of-bounds in __read_once_size include/linux/compiler.h:188 [inline] BUG: KASAN: slab-out-of-bounds in perf_event_fd_array_release+0x435/0x480 kernel/bpf/arraymap.c:544 Read of size 8 at addr ffff8801c0055140 by task syzkaller000829/3488 CPU: 0 PID: 3488 Comm: syzkaller000829 Not tainted 4.15.0-rc7-next-20180110+ #93 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __read_once_size include/linux/compiler.h:188 [inline] perf_event_fd_array_release+0x435/0x480 kernel/bpf/arraymap.c:544 bpf_map_release+0x84/0xc0 kernel/bpf/syscall.c:257 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:869 do_group_exit+0x149/0x400 kernel/exit.c:972 SYSC_exit_group kernel/exit.c:983 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:981 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x440a69 RSP: 002b:00000000007dff48 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007ffda1715470 RCX: 0000000000440a69 RDX: 0000000000440a69 RSI: 000000000000002c RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000402240 R13: 00000000004022d0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3488: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552 __do_kmalloc_node mm/slab.c:3669 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3676 kmalloc_node include/linux/slab.h:557 [inline] bpf_map_area_alloc+0x32/0x80 kernel/bpf/syscall.c:123 array_map_alloc+0x351/0xa00 kernel/bpf/arraymap.c:96 fd_array_map_alloc+0x57/0x70 kernel/bpf/arraymap.c:341 find_and_alloc_map kernel/bpf/syscall.c:105 [inline] map_create kernel/bpf/syscall.c:404 [inline] SYSC_bpf kernel/bpf/syscall.c:1805 [inline] SyS_bpf+0x7f8/0x4400 kernel/bpf/syscall.c:1782 entry_SYSCALL_64_fastpath+0x29/0xa0 Freed by task 1980: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 __cache_free mm/slab.c:3485 [inline] kfree+0xd9/0x260 mm/slab.c:3800 seq_release fs/seq_file.c:366 [inline] single_release+0x80/0xb0 fs/seq_file.c:602 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 The buggy address belongs to the object at ffff8801c0055040 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes to the right of 256-byte region [ffff8801c0055040, ffff8801c0055140) The buggy address belongs to the page: page:ffffea0007001540 count:1 mapcount:0 mapping:ffff8801c0055040 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801c0055040 0000000000000000 000000010000000c raw: ffffea000701e720 ffffea000700c7a0 ffff8801dac007c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c0055000: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff8801c0055080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8801c0055100: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
^ ffff8801c0055180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c0055200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a dumb bot. It may contain errors. See https://goo.gl/tpsmEJ for details. Direct all questions to syzkaller@googlegroups.com. syzbot will keep track of this bug report. If you forgot to add the Reported-by tag, once the fix for this bug is merged into any tree, please reply to this email with: #syz fix: exact-commit-title If you want to test a patch for this bug, please reply with: #syz test: git://repo/address.git branch and provide the patch inline or as an attachment. To mark this as a duplicate of another syzbot report, please reply with: #syz dup: exact-subject-of-another-report If it's a one-off invalid bug report, please reply with: #syz invalid Note: if the crash happens again, it will cause creation of a new bug report. Note: all commands must start from beginning of the line in the email body.