Hello, syzbot found the following issue on: HEAD commit: 9791581c Merge tag 'for-5.11-rc4-tag' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10d94027500000 kernel config: https://syzkaller.appspot.com/x/.config?x=c5f3af3f625fb042 dashboard link: https://syzkaller.appspot.com/bug?extid=da4fe66aaadd3c2e2d1c compiler: clang version 11.0.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11ad6f00d00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ffb69f500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+da4fe66aaadd3c2e2d1c@xxxxxxxxxxxxxxxxxxxxxxxxx loop0: detected capacity change from 16383 to 0 ================================================================================ UBSAN: shift-out-of-bounds in fs/exfat/super.c:471:28 shift exponent 4294967294 is too large for 32-bit type 'int' CPU: 0 PID: 8443 Comm: syz-executor876 Not tainted 5.11.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x183/0x22e lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395 exfat_read_boot_sector fs/exfat/super.c:471 [inline] __exfat_fill_super fs/exfat/super.c:556 [inline] exfat_fill_super+0x2acb/0x2d00 fs/exfat/super.c:624 get_tree_bdev+0x406/0x630 fs/super.c:1291 vfs_get_tree+0x86/0x270 fs/super.c:1496 do_new_mount fs/namespace.c:2881 [inline] path_mount+0x1937/0x2c50 fs/namespace.c:3211 do_mount fs/namespace.c:3224 [inline] __do_sys_mount fs/namespace.c:3432 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3409 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x446f8a 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:00007fff97c1b978 EFLAGS: 00000297 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff97c1b9d0 RCX: 0000000000446f8a RDX: 0000000020000000 RSI: 0000000020000340 RDI: 00007fff97c1b990 RBP: 00007fff97c1b990 R08: 00007fff97c1b9d0 R09: 00007fff00000015 R10: 0000000000000000 R11: 0000000000000297 R12: 000000000000000c R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003 ================================================================================ --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
