Hello, syzbot found the following issue on: HEAD commit: 4236f913808c Merge tag 'scsi-fixes' of git://git.kernel.or.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=160252a7980000 kernel config: https://syzkaller.appspot.com/x/.config?x=4d4311df74eee96f dashboard link: https://syzkaller.appspot.com/bug?extid=41ebd857f013384237a9 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=14ed9540580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/51b1dad228c5/disk-4236f913.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/9a7ef646b195/vmlinux-4236f913.xz kernel image: https://storage.googleapis.com/syzbot-assets/5231f6873f58/bzImage-4236f913.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/30f3d2299c08/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+41ebd857f013384237a9@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline] BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:30 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:300 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:328 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x2f3/0x2b30 lib/iov_iter.c:185 instrument_copy_to_user include/linux/instrumented.h:114 [inline] copy_to_user_iter lib/iov_iter.c:24 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:300 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] _copy_to_iter+0x2f3/0x2b30 lib/iov_iter.c:185 copy_page_to_iter+0x419/0x880 lib/iov_iter.c:362 pipe_read+0x88c/0x21a0 fs/pipe.c:327 new_sync_read fs/read_write.c:488 [inline] vfs_read+0xcdf/0xf50 fs/read_write.c:569 ksys_read+0x24f/0x4c0 fs/read_write.c:712 __do_sys_read fs/read_write.c:722 [inline] __se_sys_read fs/read_write.c:720 [inline] __x64_sys_read+0x93/0xe0 fs/read_write.c:720 x64_sys_call+0x3055/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: memcpy_to_iter lib/iov_iter.c:65 [inline] iterate_bvec include/linux/iov_iter.h:123 [inline] iterate_and_advance2 include/linux/iov_iter.h:304 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] _copy_to_iter+0xe5a/0x2b30 lib/iov_iter.c:185 copy_page_to_iter+0x419/0x880 lib/iov_iter.c:362 shmem_file_read_iter+0xa09/0x12b0 mm/shmem.c:3164 do_iter_readv_writev+0x88a/0xa30 vfs_iter_read+0x278/0x760 fs/read_write.c:923 lo_read_simple drivers/block/loop.c:283 [inline] do_req_filebacked drivers/block/loop.c:516 [inline] loop_handle_cmd drivers/block/loop.c:1910 [inline] loop_process_work+0x20fc/0x3750 drivers/block/loop.c:1945 loop_workfn+0x48/0x60 drivers/block/loop.c:1969 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391 kthread+0x3e2/0x540 kernel/kthread.c:389 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was stored to memory at: memcpy_from_iter lib/iov_iter.c:73 [inline] iterate_bvec include/linux/iov_iter.h:123 [inline] iterate_and_advance2 include/linux/iov_iter.h:304 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] copy_page_from_iter_atomic+0x1299/0x30c0 lib/iov_iter.c:481 copy_folio_from_iter_atomic include/linux/uio.h:201 [inline] generic_perform_write+0x8d1/0x1080 mm/filemap.c:4066 shmem_file_write_iter+0x2ba/0x2f0 mm/shmem.c:3218 do_iter_readv_writev+0x88a/0xa30 vfs_iter_write+0x44d/0xd40 fs/read_write.c:988 lo_write_bvec drivers/block/loop.c:243 [inline] lo_write_simple drivers/block/loop.c:264 [inline] do_req_filebacked drivers/block/loop.c:511 [inline] loop_handle_cmd drivers/block/loop.c:1910 [inline] loop_process_work+0x15e6/0x3750 drivers/block/loop.c:1945 loop_workfn+0x48/0x60 drivers/block/loop.c:1969 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391 kthread+0x3e2/0x540 kernel/kthread.c:389 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was created at: __alloc_pages_noprof+0x9a7/0xe00 mm/page_alloc.c:4756 alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2265 alloc_pages_noprof mm/mempolicy.c:2345 [inline] folio_alloc_noprof+0x1db/0x310 mm/mempolicy.c:2352 filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1010 __filemap_get_folio+0xac4/0x1550 mm/filemap.c:1952 block_write_begin+0x6e/0x2b0 fs/buffer.c:2226 exfat_write_begin+0xfb/0x400 fs/exfat/inode.c:434 exfat_extend_valid_size fs/exfat/file.c:553 [inline] exfat_file_write_iter+0x474/0xfb0 fs/exfat/file.c:588 do_iter_readv_writev+0x88a/0xa30 vfs_writev+0x56a/0x14f0 fs/read_write.c:1064 do_pwritev fs/read_write.c:1165 [inline] __do_sys_pwritev2 fs/read_write.c:1224 [inline] __se_sys_pwritev2+0x280/0x470 fs/read_write.c:1215 __x64_sys_pwritev2+0x11f/0x1a0 fs/read_write.c:1215 x64_sys_call+0x2edb/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:329 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Bytes 0-1023 of 1024 are uninitialized Memory access of size 1024 starts at ffff88801d942400 Data copied to user address 0000555560b53ba0 CPU: 1 UID: 0 PID: 5798 Comm: syz-executor Not tainted 6.12.0-rc5-syzkaller-00047-g4236f913808c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 ===================================================== --- 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
