Running a debug build of the kernel while running regression tests for cifs.ko on 5.11, I noticed this message logged which looks like it is still a probably valid bug in truncate_pagecache in mm/truncate.c in current kernel as well loff_t holebegin = round_up(newsize, PAGE_SIZE); This was what was in dmesg: [23907.325526] UBSAN: signed-integer-overflow in mm/truncate.c:833:9 [23907.325532] 9223372036854775807 + 1 cannot be represented in type 'long long int' [23907.325536] CPU: 2 PID: 13007 Comm: xfs_io Not tainted 5.11.22 #1 [23907.325540] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [23907.325543] Call Trace: [23907.325548] dump_stack+0x8d/0xb5 [23907.325560] ubsan_epilogue+0x5/0x50 [23907.325568] handle_overflow+0xa3/0xb0 [23907.325581] truncate_pagecache+0x8a/0x90 [23907.325587] cifs_set_file_size+0xdb/0x2c0 [cifs] [23907.325749] cifs_setattr+0xc93/0x1260 [cifs] [23907.325799] notify_change+0x35b/0x4a0 [23907.325811] ? do_truncate+0x5e/0x90 [23907.325817] do_truncate+0x5e/0x90 [23907.325828] do_sys_ftruncate+0x143/0x280 [23907.325837] do_syscall_64+0x33/0x40 [23907.325842] entry_SYSCALL_64_after_hwframe+0x44/0xa9 -- Thanks, Steve