[syzbot] UBSAN: array-index-out-of-bounds in ima_inode_setxattr

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    33e65b1f975c Add linux-next specific files for 20210819
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1546c341300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3022de5bd1dbc8f5
dashboard link: https://syzkaller.appspot.com/bug?extid=e8bafe7b82c739eaf153
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15767d41300000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13582731300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e8bafe7b82c739eaf153 at syzkaller.appspotmail.com

================================================================================
UBSAN: array-index-out-of-bounds in security/integrity/ima/ima_appraise.c:621:36
index 222 is out of range for type 'char *[20]'
CPU: 1 PID: 6550 Comm: syz-executor680 Not tainted 5.14.0-rc6-next-20210819-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x5a lib/ubsan.c:151
 __ubsan_handle_out_of_bounds.cold+0x64/0x70 lib/ubsan.c:291
 validate_hash_algo security/integrity/ima/ima_appraise.c:621 [inline]
 ima_inode_setxattr+0x536/0x540 security/integrity/ima/ima_appraise.c:656
 security_inode_setxattr+0x148/0x240 security/security.c:1355
 __vfs_setxattr_locked+0xa7/0x260 fs/xattr.c:266
 vfs_setxattr+0x14e/0x350 fs/xattr.c:301
 setxattr+0x21b/0x2b0 fs/xattr.c:575
 path_setxattr+0x19d/0x1d0 fs/xattr.c:595
 __do_sys_lsetxattr fs/xattr.c:618 [inline]
 __se_sys_lsetxattr fs/xattr.c:614 [inline]
 __x64_sys_lsetxattr+0xbd/0x150 fs/xattr.c:614
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43ee89
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe96b06768 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ee89
RDX: 0000000020000140 RSI: 00000000200000c0 RDI: 0000000020000000
RBP: 0000000000402e70 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000246 R12: 0000000000402f00
R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488
================================================================================
----------------
Code disassembly (best guess):
   0:	28 c3                	sub    %al,%bl
   2:	e8 2a 14 00 00       	callq  0x1431
   7:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
   e:	00 00 00 
  11:	48 89 f8             	mov    %rdi,%rax
  14:	48 89 f7             	mov    %rsi,%rdi
  17:	48 89 d6             	mov    %rdx,%rsi
  1a:	48 89 ca             	mov    %rcx,%rdx
  1d:	4d 89 c2             	mov    %r8,%r10
  20:	4d 89 c8             	mov    %r9,%r8
  23:	4c 8b 4c 24 08       	mov    0x8(%rsp),%r9
  28:	0f 05                	syscall 
  2a:	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax <-- trapping instruction
  30:	73 01                	jae    0x33
  32:	c3                   	retq   
  33:	48 c7 c1 c0 ff ff ff 	mov    $0xffffffffffffffc0,%rcx
  3a:	f7 d8                	neg    %eax
  3c:	64 89 01             	mov    %eax,%fs:(%rcx)
  3f:	48                   	rex.W


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