Hello, syzbot found the following issue on: HEAD commit: 90ea0df61c98 kmsan: add test_stackdepot_roundtrip git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=17f50711c80000 kernel config: https://syzkaller.appspot.com/x/.config?x=bfbc1ed9c2e8818f dashboard link: https://syzkaller.appspot.com/bug?extid=fbc7d315ac68168b2bd6 compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/904650d5b897/disk-90ea0df6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/421ab8e12064/vmlinux-90ea0df6.xz kernel image: https://storage.googleapis.com/syzbot-assets/170979c11e5a/bzImage-90ea0df6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fbc7d315ac68168b2bd6@xxxxxxxxxxxxxxxxxxxxxxxxx loop3: detected capacity change from 0 to 256 ===================================================== BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xc0/0x100 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:121 [inline] _copy_to_user+0xc0/0x100 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:169 [inline] do_sys_name_to_handle fs/fhandle.c:73 [inline] __do_sys_name_to_handle_at fs/fhandle.c:109 [inline] __se_sys_name_to_handle_at+0x7c8/0x910 fs/fhandle.c:93 __ia32_sys_name_to_handle_at+0xe3/0x150 fs/fhandle.c:93 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Uninit was created at: slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774 slab_alloc_node mm/slub.c:3452 [inline] __kmem_cache_alloc_node+0x518/0x920 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:966 [inline] __kmalloc+0x121/0x3c0 mm/slab_common.c:980 kmalloc include/linux/slab.h:584 [inline] do_sys_name_to_handle fs/fhandle.c:40 [inline] __do_sys_name_to_handle_at fs/fhandle.c:109 [inline] __se_sys_name_to_handle_at+0x3a2/0x910 fs/fhandle.c:93 __ia32_sys_name_to_handle_at+0xe3/0x150 fs/fhandle.c:93 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Bytes 18-19 of 20 are uninitialized Memory access of size 20 starts at ffff88809f7ed5c0 Data copied to user address 0000000020000300 CPU: 1 PID: 6126 Comm: syz-executor.3 Not tainted 6.3.0-rc3-syzkaller-g90ea0df61c98 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 ===================================================== --- 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.
