UBSAN: undefined-behaviour in arch_uprobe_analyze_insn

Status: upstream: reported C repro on 2020/09/17 01:47
Reported-by: syzbot+a3f0727d419f82e6b9b7@syzkaller.appspotmail.com
First crash: 2167d, last: 2132d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
audit: type=1400 audit(1603298439.994:8): avc:  denied  { execmem } for  pid=8114 comm="syz-executor178" 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: 8114 Comm: syz-executor178 Not tainted 4.19.152-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: 0033:0x440379
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff00a08798 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440379
RDX: 0000000000000000 RSI: 0000000000003000 RDI: 0000000020007000
RBP: 00000000006ca018 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000412 R11: 0000000000000246 R12: 0000000000401b80
R13: 0000000000401c10 R14: 0000000000000000 R15: 0000000000000000
==========================================================

Crashes (288):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/10/21 16:42 linux-4.19.y ad326970d25c 99c64d5c .config console log report syz C ci2-linux-4-19
2020/10/06 00:28 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report syz C ci2-linux-4-19
2020/10/05 18:40 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report syz C ci2-linux-4-19
2020/10/02 10:17 linux-4.19.y b09c34517e1a 9602ddf4 .config console log report syz C ci2-linux-4-19
2020/09/20 16:48 linux-4.19.y 015e94d0e37b 9564d2e9 .config console log report syz C ci2-linux-4-19
2020/10/21 19:20 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 16:36 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 14:29 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 08:08 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 03:41 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 05:10 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 00:29 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 23:14 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 06:41 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/17 00:01 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 21:27 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 07:26 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 03:49 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/16 00:10 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 22:43 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 07:38 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 15:24 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 14:35 linux-4.19.y a1b977b49b66 bd69ee0d .config console log report info ci2-linux-4-19
2020/10/13 09:59 linux-4.19.y a1b977b49b66 bd69ee0d .config console log report info ci2-linux-4-19
2020/10/12 14:20 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/12 11:25 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/12 09:33 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/11 08:39 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/11 08:27 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/10 16:58 linux-4.19.y a1b977b49b66 b74c49a6 .config console log report info ci2-linux-4-19
2020/10/10 08:55 linux-4.19.y a1b977b49b66 b74c49a6 .config console log report info ci2-linux-4-19
2020/10/09 10:46 linux-4.19.y a1b977b49b66 fa79ed2a .config console log report info ci2-linux-4-19
2020/10/08 08:26 linux-4.19.y a1b977b49b66 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/08 00:14 linux-4.19.y a1b977b49b66 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/07 00:26 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 14:26 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 06:40 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 04:57 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 03:21 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 21:48 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 18:29 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 15:20 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 06:39 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report info ci2-linux-4-19
2020/10/04 11:07 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report info ci2-linux-4-19
2020/10/04 05:33 linux-4.19.y b09c34517e1a 1a3f9408 .config console log report info ci2-linux-4-19
2020/10/03 20:54 linux-4.19.y b09c34517e1a 1a3f9408 .config console log report info ci2-linux-4-19
2020/10/03 18:17 linux-4.19.y b09c34517e1a 1a3f9408 .config console log report info ci2-linux-4-19
2020/10/03 08:14 linux-4.19.y b09c34517e1a 2653fa43 .config console log report info ci2-linux-4-19
2020/10/02 21:41 linux-4.19.y b09c34517e1a 062c9832 .config console log report info ci2-linux-4-19
2020/10/02 16:22 linux-4.19.y b09c34517e1a 062c9832 .config console log report info ci2-linux-4-19
2020/10/02 10:41 linux-4.19.y b09c34517e1a 9602ddf4 .config console log report info ci2-linux-4-19
2020/10/02 08:31 linux-4.19.y b09c34517e1a 9602ddf4 .config console log report info ci2-linux-4-19
2020/09/17 01:47 linux-4.19.y a87f96283793 8247808b .config console log report info ci2-linux-4-19
* Struck through repros no longer work on HEAD.