Hello, syzbot found the following issue on: HEAD commit: fbafc3e621c3 Merge tag 'for_linus' of git://git.kernel.org.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=173df3e9e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=e0c7078a6b901aa3 dashboard link: https://syzkaller.appspot.com/bug?extid=d7521c1e3841ed075a42 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=1300b4a1e80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=130b0379e80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/1520f7b6daa4/disk-fbafc3e6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8b490af009d5/vmlinux-fbafc3e6.xz kernel image: https://storage.googleapis.com/syzbot-assets/202ca200f4a4/bzImage-fbafc3e6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d7521c1e3841ed075a42@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+0x21c6/0x6530 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+0x21c6/0x6530 drivers/virtio/virtio_ring.c:2210 virtqueue_add_sgs+0x186/0x1a0 drivers/virtio/virtio_ring.c:2244 __virtscsi_add_cmd drivers/scsi/virtio_scsi.c:467 [inline] virtscsi_add_cmd+0x838/0xad0 drivers/scsi/virtio_scsi.c:501 virtscsi_queuecommand+0x896/0xa60 drivers/scsi/virtio_scsi.c:598 scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1516 [inline] scsi_queue_rq+0x4874/0x5790 drivers/scsi/scsi_lib.c:1758 blk_mq_dispatch_rq_list+0x13f8/0x3600 block/blk-mq.c:2049 __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+0x10af/0x2500 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0x160/0x2d0 block/blk-mq-sched.c:333 blk_mq_run_work_fn+0xd0/0x280 block/blk-mq.c:2434 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2700 worker_thread+0xf45/0x1490 kernel/workqueue.c:2781 kthread+0x3ed/0x540 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Uninit was created at: __alloc_pages+0x9a4/0xe00 mm/page_alloc.c:4591 alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133 alloc_pages mm/mempolicy.c:2204 [inline] folio_alloc+0x1da/0x380 mm/mempolicy.c:2211 filemap_alloc_folio+0xa5/0x430 mm/filemap.c:974 __filemap_get_folio+0xa5a/0x1760 mm/filemap.c:1918 ext4_da_write_begin+0x7f8/0xec0 fs/ext4/inode.c:2891 generic_perform_write+0x3f5/0xc40 mm/filemap.c:3918 ext4_buffered_write_iter+0x564/0xaa0 fs/ext4/file.c:299 ext4_file_write_iter+0x20f/0x3460 __kernel_write_iter+0x329/0x930 fs/read_write.c:517 dump_emit_page fs/coredump.c:888 [inline] dump_user_range+0x593/0xcd0 fs/coredump.c:915 elf_core_dump+0x528d/0x5a40 fs/binfmt_elf.c:2077 do_coredump+0x32c9/0x4920 fs/coredump.c:764 get_signal+0x2185/0x2d10 kernel/signal.c:2890 arch_do_signal_or_restart+0x53/0xca0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop+0xe8/0x320 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x163/0x220 kernel/entry/common.c:204 irqentry_exit_to_user_mode+0xd/0x30 kernel/entry/common.c:309 irqentry_exit+0x16/0x40 kernel/entry/common.c:412 exc_page_fault+0x246/0x6f0 arch/x86/mm/fault.c:1564 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:570 Bytes 0-4095 of 4096 are uninitialized Memory access of size 4096 starts at ffff88812c79c000 CPU: 0 PID: 997 Comm: kworker/0:1H Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 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 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
