audit: type=1400 audit(1601943999.552:8): avc:  denied  { execmem } for  pid=6459 comm="syz-executor454" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
================================================================================
UBSAN: Undefined behaviour in arch/x86/kernel/uprobes.c:276:56
index 4 is out of range for type 'insn_byte_t [4]'
CPU: 1 PID: 6460 Comm: syz-executor454 Not tainted 4.19.149-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x22c/0x33e lib/dump_stack.c:118
 ubsan_epilogue+0xe/0x3a lib/ubsan.c:161
 __ubsan_handle_out_of_bounds.cold+0x63/0x6f lib/ubsan.c:383
 is_prefix_bad arch/x86/kernel/uprobes.c:276 [inline]
 uprobe_init_insn arch/x86/kernel/uprobes.c:299 [inline]
 arch_uprobe_analyze_insn+0x9d8/0xaa0 arch/x86/kernel/uprobes.c:868
 prepare_uprobe kernel/events/uprobes.c:611 [inline]
 install_breakpoint kernel/events/uprobes.c:654 [inline]
 uprobe_mmap+0x8c2/0xa70 kernel/events/uprobes.c:1096
 mmap_region+0x552/0x1510 mm/mmap.c:1803
 do_mmap+0x8e8/0x1080 mm/mmap.c:1530
 do_mmap_pgoff include/linux/mm.h:2326 [inline]
 vm_mmap_pgoff+0x197/0x200 mm/util.c:357
 ksys_mmap_pgoff+0x2d1/0x660 mm/mmap.c:1580
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441379
Code: e8 3c ad 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 0f 83 1b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffec1e96758 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441379
RDX: 0000000000000000 RSI: 0000000000003000 RDI: 0000000020007000
RBP: 00000000006cc018 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000412 R11: 0000000000000246 R12: 0000000000402120
R13: 00000000004021b0 R14: 0000000000000000 R15: 0000000000000000
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