audit: type=1400 audit(1600622589.906:8): avc: denied { execmem } for pid=6493 comm="syz-executor855" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 erofs: read_super, device -> /dev/loop0 erofs: options -> ================================================================================ UBSAN: Undefined behaviour in drivers/staging/erofs/super.c:122:3 shift exponent 55 is too large for 32-bit type 'int' CPU: 0 PID: 6493 Comm: syz-executor855 Not tainted 4.19.146-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_shift_out_of_bounds.cold+0x1c4/0x250 lib/ubsan.c:422 superblock_read drivers/staging/erofs/super.c:122 [inline] erofs_read_super drivers/staging/erofs/super.c:356 [inline] erofs_fill_super+0x397/0x12fc drivers/staging/erofs/super.c:499 mount_bdev+0x2fc/0x3b0 fs/super.c:1158 erofs_mount+0x8c/0xc0 drivers/staging/erofs/super.c:512 mount_fs+0xa3/0x318 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x51c/0x2f10 fs/namespace.c:2799 ksys_mount+0xcf/0x130 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3026 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446d4a Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007ffe5db93678 EFLAGS: 00000297 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffe5db936d0 RCX: 0000000000446d4a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffe5db93690 RBP: 00007ffe5db93690 R08: 00007ffe5db936d0 R09: 00007ffe00000015 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000002 R13: 0000000000000004 R14: 0000000000000003 R15: 00000000