Hello, syzbot found the following issue on: HEAD commit: 0de63bb7d919 Merge tag 'pull-fix' of git://git.kernel.org/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=132078a4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=1909f2f0d8e641ce dashboard link: https://syzkaller.appspot.com/bug?extid=fe375f77ba1a6ab944b6 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eca3df980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10974f64580000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-0de63bb7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1142009a30a7/vmlinux-0de63bb7.xz kernel image: https://storage.googleapis.com/syzbot-assets/5d9e46a8998d/bzImage-0de63bb7.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/e651a39ab132/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fe375f77ba1a6ab944b6@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in lib/xarray.c:147:16 shift exponent 252 is too large for 64-bit type 'unsigned long' CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: loop0 loop_rootcg_workfn Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468 get_offset lib/xarray.c:147 [inline] xas_descend lib/xarray.c:207 [inline] xas_create+0x1832/0x1ae0 lib/xarray.c:695 xas_store+0x96/0x1870 lib/xarray.c:794 shmem_add_to_page_cache+0x89d/0xcc0 mm/shmem.c:897 shmem_alloc_and_add_folio+0x968/0x1090 mm/shmem.c:1928 shmem_get_folio_gfp+0x621/0x1840 mm/shmem.c:2522 shmem_get_folio mm/shmem.c:2628 [inline] shmem_write_begin+0x165/0x350 mm/shmem.c:3278 generic_perform_write+0x346/0x990 mm/filemap.c:4189 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3454 do_iter_readv_writev+0x71a/0x9d0 vfs_iter_write+0x23e/0x600 fs/read_write.c:974 lo_write_bvec drivers/block/loop.c:245 [inline] lo_write_simple drivers/block/loop.c:266 [inline] do_req_filebacked drivers/block/loop.c:520 [inline] loop_handle_cmd drivers/block/loop.c:1929 [inline] loop_process_work+0x1429/0x21c0 drivers/block/loop.c:1964 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> ---[ end trace ]--- --- 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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
