loop2: detected capacity change from 0 to 256
exFAT-fs (loop2): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
exFAT-fs (loop2): Medium has reported failures. Some data may be lost.
================================================================================
UBSAN: shift-out-of-bounds in fs/exfat/super.c:529:38
shift exponent 185 is too large for 32-bit type 'int'
CPU: 1 PID: 599 Comm: syz.2.27 Not tainted 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 dump_stack+0x15/0x18 lib/dump_stack.c:113
 ubsan_epilogue lib/ubsan.c:151 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3e1/0x440 lib/ubsan.c:321
 exfat_read_boot_sector fs/exfat/super.c:529 [inline]
 __exfat_fill_super fs/exfat/super.c:585 [inline]
 exfat_fill_super+0x2b3a/0x2b80 fs/exfat/super.c:649
 get_tree_bdev+0x43d/0x670 fs/super.c:1366
 exfat_get_tree+0x1c/0x20 fs/exfat/super.c:721
 vfs_get_tree+0x88/0x290 fs/super.c:1573
 do_new_mount+0x2ba/0xb30 fs/namespace.c:3056
 path_mount+0x671/0x1070 fs/namespace.c:3386
 do_mount fs/namespace.c:3399 [inline]
 __do_sys_mount fs/namespace.c:3607 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3584
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3584
 x64_sys_call+0x49d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5a9e58f90a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5a9f347e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5a9f347ef0 RCX: 00007f5a9e58f90a
RDX: 0000200000000000 RSI: 0000200000000240 RDI: 00007f5a9f347eb0
RBP: 0000200000000000 R08: 00007f5a9f347ef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000240
R13: 00007f5a9f347eb0 R14: 00000000000014fe R15: 0000200000000600
 </TASK>
================================================================================
exFAT-fs (loop2): unable to set blocksize 33554432
exFAT-fs (loop2): failed to read boot sector
exFAT-fs (loop2): failed to recognize exfat type