Hello, syzbot found the following issue on: HEAD commit: 614da38e2f7a Merge tag 'hid-for-linus-2024051401' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=116670b6980000 kernel config: https://syzkaller.appspot.com/x/.config?x=f5d2cbf33633f507 dashboard link: https://syzkaller.appspot.com/bug?extid=64dd7c1298e0b0da9299 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/89eafb874b71/disk-614da38e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/356000512ad9/vmlinux-614da38e.xz kernel image: https://storage.googleapis.com/syzbot-assets/839c73939115/bzImage-614da38e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+64dd7c1298e0b0da9299@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in vring_map_one_sg drivers/virtio/virtio_ring.c:380 [inline] BUG: KMSAN: uninit-value in virtqueue_add_split drivers/virtio/virtio_ring.c:614 [inline] BUG: KMSAN: uninit-value in virtqueue_add+0x1e86/0x65c0 drivers/virtio/virtio_ring.c:2210 vring_map_one_sg drivers/virtio/virtio_ring.c:380 [inline] virtqueue_add_split drivers/virtio/virtio_ring.c:614 [inline] virtqueue_add+0x1e86/0x65c0 drivers/virtio/virtio_ring.c:2210 virtqueue_add_sgs+0x186/0x1b0 drivers/virtio/virtio_ring.c:2244 __virtscsi_add_cmd drivers/scsi/virtio_scsi.c:471 [inline] virtscsi_add_cmd+0x838/0xad0 drivers/scsi/virtio_scsi.c:505 virtscsi_queuecommand+0x898/0xa60 drivers/scsi/virtio_scsi.c:602 scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1609 [inline] scsi_queue_rq+0x4cc7/0x5a80 drivers/scsi/scsi_lib.c:1851 blk_mq_dispatch_rq_list+0x79b/0x3440 block/blk-mq.c:2037 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline] __blk_mq_sched_dispatch_requests+0x11b7/0x26e0 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0x12f/0x270 block/blk-mq-sched.c:331 blk_mq_run_work_fn+0xd0/0x280 block/blk-mq.c:2420 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa81/0x1bd0 kernel/workqueue.c:3348 worker_thread+0xea5/0x1560 kernel/workqueue.c:3429 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:122 [inline] iterate_and_advance2 include/linux/iov_iter.h:249 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] copy_page_from_iter_atomic+0x12b7/0x2ae0 lib/iov_iter.c:481 generic_perform_write+0x4c1/0xc60 mm/filemap.c:3982 ext4_buffered_write_iter+0x564/0xaa0 fs/ext4/file.c:299 ext4_file_write_iter+0x208/0x3450 __kernel_write_iter+0x64d/0xc80 fs/read_write.c:523 dump_emit_page fs/coredump.c:895 [inline] dump_user_range+0x8dc/0xee0 fs/coredump.c:956 elf_core_dump+0x57c7/0x5ae0 fs/binfmt_elf.c:2083 do_coredump+0x32d5/0x4920 fs/coredump.c:769 get_signal+0x267e/0x2d00 kernel/signal.c:2896 arch_do_signal_or_restart+0x53/0xcb0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x5d/0x160 kernel/entry/common.c:218 do_syscall_64+0xdc/0x1e0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598 alloc_pages_mpol+0x299/0x990 mm/mempolicy.c:2264 alloc_pages+0x1bf/0x1e0 mm/mempolicy.c:2335 dump_user_range+0x4a/0xee0 fs/coredump.c:940 elf_core_dump+0x57c7/0x5ae0 fs/binfmt_elf.c:2083 do_coredump+0x32d5/0x4920 fs/coredump.c:769 get_signal+0x267e/0x2d00 kernel/signal.c:2896 arch_do_signal_or_restart+0x53/0xcb0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x5d/0x160 kernel/entry/common.c:218 do_syscall_64+0xdc/0x1e0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Bytes 0-4095 of 4096 are uninitialized Memory access of size 4096 starts at ffff88804137f000 CPU: 0 PID: 55 Comm: kworker/0:1H Not tainted 6.9.0-syzkaller-02707-g614da38e2f7a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: kblockd blk_mq_run_work_fn ===================================================== --- 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 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
