audit: type=1400 audit(1570155495.816:7): avc: denied { map } for pid=1788 comm="syz-executor724" path="/root/syz-executor724887516" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
audit: type=1400 audit(1570155495.816:8): avc: denied { prog_load } for pid=1788 comm="syz-executor724" 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
audit: type=1400 audit(1570155495.876:9): avc: denied { prog_run } for pid=1788 comm="syz-executor724" 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 ____bpf_skb_change_head net/core/filter.c:2423 [inline]
BUG: KASAN: slab-out-of-bounds in bpf_skb_change_head+0x4ea/0x600 net/core/filter.c:2419
Read of size 4 at addr ffff8881d5a1bfb8 by task syz-executor724/1788
CPU: 0 PID: 1788 Comm: syz-executor724 Not tainted 4.14.146+ #0
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xca/0x134 lib/dump_stack.c:53
print_address_description+0x60/0x226 mm/kasan/report.c:187
__kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316
____bpf_skb_change_head net/core/filter.c:2423 [inline]
bpf_skb_change_head+0x4ea/0x600 net/core/filter.c:2419
___bpf_prog_run+0x2478/0x5510 kernel/bpf/core.c:1095
Allocated by task 1586:
save_stack mm/kasan/common.c:76 [inline]
set_track mm/kasan/common.c:85 [inline]
__kasan_kmalloc.part.0+0x53/0xc0 mm/kasan/common.c:501
slab_post_alloc_hook mm/slab.h:439 [inline]
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2800 [inline]
kmem_cache_alloc+0xee/0x360 mm/slub.c:2805
kmem_cache_zalloc include/linux/slab.h:651 [inline]
mmap_region+0x56e/0xfb0 mm/mmap.c:1700
do_mmap+0x548/0xb80 mm/mmap.c:1510
do_mmap_pgoff include/linux/mm.h:2209 [inline]
vm_mmap_pgoff+0x177/0x1c0 mm/util.c:333
SYSC_mmap_pgoff mm/mmap.c:1560 [inline]
SyS_mmap_pgoff+0x146/0x1b0 mm/mmap.c:1518
do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
0xffffffffffffffff
Freed by task 1586:
save_stack mm/kasan/common.c:76 [inline]
set_track mm/kasan/common.c:85 [inline]
__kasan_slab_free+0x164/0x210 mm/kasan/common.c:463
slab_free_hook mm/slub.c:1407 [inline]
slab_free_freelist_hook mm/slub.c:1458 [inline]
slab_free mm/slub.c:3039 [inline]
kmem_cache_free+0xd7/0x3b0 mm/slub.c:3055
remove_vma+0x117/0x160 mm/mmap.c:177
exit_mmap+0x2a0/0x440 mm/mmap.c:3083
__mmput kernel/fork.c:940 [inline]
mmput+0xeb/0x370 kernel/fork.c:961
exit_mm kernel/exit.c:545 [inline]
do_exit+0x905/0x2a20 kernel/exit.c:862
do_group_exit+0x100/0x2e0 kernel/exit.c:978
SYSC_exit_group kernel/exit.c:989 [inline]
SyS_exit_group+0x19/0x20 kernel/exit.c:987
do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
0xffffffffffffffff
The buggy address belongs to the object at ffff8881d5a1be88
which belongs to the cache vm_area_struct of size 184
The buggy address is located 120 bytes to the right of
184-byte region [ffff8881d5a1be88, ffff8881d5a1bf40)
The buggy address belongs to the page:
page:ffffea00075686c0 count:1 mapcount:0 mapping: (null) index:0x0
flags: 0x4000000000000200(slab)
raw: 4000000000000200 0000000000000000 0000000000000000 0000000100100010
raw: dead000000000100 dead000000000200 ffff8881da952a00 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881d5a1be80: fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d5a1bf00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8881d5a1bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8881d5a1c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d5a1c080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================