KASAN: use-after-free Read in bpf_prog_kallsyms

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KASAN: use-after-free Read in bpf_prog_kallsyms_add bpf	syz	error	inconclusive	120	1843d	2078d	12/26	fixed on 2019/09/06 20:45
linux-4.19	KASAN: use-after-free Read in bpf_prog_kallsyms_add				2	1706d	1768d	0/1	auto-closed as invalid on 2020/01/14 14:34

================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:183 [inline] BUG: KASAN: use-after-free in list_empty include/linux/list.h:203 [inline] BUG: KASAN: use-after-free in bpf_prog_ksym_node_add kernel/bpf/core.c:369 [inline] BUG: KASAN: use-after-free in bpf_prog_kallsyms_add+0x735/0x7b0 kernel/bpf/core.c:401 Read of size 8 at addr ffff8880a72b8148 by task syz-executor.3/20056 netlink: 11 bytes leftover after parsing attributes in process `syz-executor.1'. CPU: 1 PID: 20056 Comm: syz-executor.3 Not tainted 4.14.141 #37 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+0x138/0x197 lib/dump_stack.c:53 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 __read_once_size include/linux/compiler.h:183 [inline] list_empty include/linux/list.h:203 [inline] bpf_prog_ksym_node_add kernel/bpf/core.c:369 [inline] bpf_prog_kallsyms_add+0x735/0x7b0 kernel/bpf/core.c:401 bpf_prog_load+0x78f/0xf30 kernel/bpf/syscall.c:1082 SYSC_bpf kernel/bpf/syscall.c:1503 [inline] SyS_bpf+0x433/0x2da8 kernel/bpf/syscall.c:1469 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459879 RSP: 002b:00007face409bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879 RDX: 0000000000000048 RSI: 00000000200054c0 RDI: 0000000000000005 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007face409c6d4 R13: 00000000004bfcdc R14: 00000000004d19d8 R15: 00000000ffffffff Allocated by task 20056: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] bpf_prog_alloc+0x180/0x1e0 kernel/bpf/core.c:89 bpf_prog_load+0x292/0xf30 kernel/bpf/syscall.c:1030 SYSC_bpf kernel/bpf/syscall.c:1503 [inline] SyS_bpf+0x433/0x2da8 kernel/bpf/syscall.c:1469 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 18: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 bpf_jit_free+0x89/0x310 bpf_prog_free_deferred+0x31/0x40 kernel/bpf/core.c:1480 process_one_work+0x863/0x1600 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 The buggy address belongs to the object at ffff8880a72b8100 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 72 bytes inside of 192-byte region [ffff8880a72b8100, ffff8880a72b81c0) The buggy address belongs to the page: page:ffffea00029cae00 count:1 mapcount:0 mapping:ffff8880a72b8000 index:0xffff8880a72b8200 flags: 0x1fffc0000000100(slab) raw: 01fffc0000000100 ffff8880a72b8000 ffff8880a72b8200 000000010000000c raw: ffffea00017c1060 ffffea00028385a0 ffff8880aa800040 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: kobject: 'kvm' (ffff8880a71ac010): fill_kobj_path: path = '/devices/virtual/misc/kvm' ffff8880a72b8000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a72b8080: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc >ffff8880a72b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a72b8180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880a72b8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================