On Thu, Nov 8, 2018 at 8:48 AM, syzbot <[email protected]> wrote: >> On Tue, May 15, 2018 at 9:26 AM, syzbot >> <[email protected]> wrote: >>> >>> Hello, > > >>> syzbot found the following crash on: > > >>> HEAD commit: e2ab7e8abba4 kmsan: temporarily disable >>> visitAsmInstructio.. >>> git tree: https://github.com/google/kmsan.git/master >>> console output: https://syzkaller.appspot.com/x/log.txt?x=158135db800000 >>> kernel config: >>> https://syzkaller.appspot.com/x/.config?x=5bf8b7964e37a698 >>> dashboard link: >>> https://syzkaller.appspot.com/bug?extid=fed4435f163beccc67eb >>> compiler: clang version 7.0.0 (trunk 329391) >>> syzkaller >>> repro:https://syzkaller.appspot.com/x/repro.syz?x=17a2f91b800000 >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17bd452b800000 > > >>> IMPORTANT: if you fix the bug, please add the following tag to the >>> commit: >>> Reported-by: [email protected] > > >> #syz dup: KMSAN: kernel-infoleak in vcs_read > > > Can't dup bug to a bug in different reporting (upstream->moderation).Please > dup syzbot bugs only onto syzbot bugs for the same kernel/reporting.
Let's try this: #syz fix: vt: prevent leaking uninitialized data to userspace via /dev/vcs* >>> ================================================================== >>> BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 >>> [inline] >>> BUG: KMSAN: uninit-value in vcs_read+0x18ba/0x1cc0 >>> drivers/tty/vt/vc_screen.c:352 >>> CPU: 1 PID: 3501 Comm: syzkaller315412 Not tainted 4.16.0+ #82 >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >>> Google 01/01/2011 >>> Call Trace: >>> __dump_stack lib/dump_stack.c:17 [inline] >>> dump_stack+0x185/0x1d0 lib/dump_stack.c:53 >>> kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 >>> kmsan_internal_check_memory+0x125/0x1d0 mm/kmsan/kmsan.c:1157 >>> kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199 >>> copy_to_user include/linux/uaccess.h:184 [inline] >>> vcs_read+0x18ba/0x1cc0 drivers/tty/vt/vc_screen.c:352 >>> __vfs_read+0x19f/0x8e0 fs/read_write.c:411 >>> vfs_read+0x36c/0x6c0 fs/read_write.c:447 >>> SYSC_pread64+0x275/0x310 fs/read_write.c:611 >>> SyS_pread64+0x65/0x90 fs/read_write.c:598 >>> do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 >>> entry_SYSCALL_64_after_hwframe+0x3d/0xa2 >>> RIP: 0033:0x443d39 >>> RSP: 002b:00007ffcbd3c35f8 EFLAGS: 00000213 ORIG_RAX: 0000000000000011 >>> RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d39 >>> RDX: 0000000000000083 RSI: 0000000020000140 RDI: 0000000000000003 >>> RBP: 00000000006ce018 R08: 00000000004002e0 R09: 00000000004002e0 >>> R10: 0000000000000000 R11: 0000000000000213 R12: 00000000004019e0 >>> R13: 0000000000401a70 R14: 0000000000000000 R15: 0000000000000000 > > >>> Uninit was stored to memory at: >>> kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] >>> kmsan_save_stack mm/kmsan/kmsan.c:293 [inline] >>> kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684 >>> __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521 >>> vcs_read+0xd01/0x1cc0 drivers/tty/vt/vc_screen.c:274 >>> __vfs_read+0x19f/0x8e0 fs/read_write.c:411 >>> vfs_read+0x36c/0x6c0 fs/read_write.c:447 >>> SYSC_pread64+0x275/0x310 fs/read_write.c:611 >>> SyS_pread64+0x65/0x90 fs/read_write.c:598 >>> do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 >>> entry_SYSCALL_64_after_hwframe+0x3d/0xa2 >>> Uninit was created at: >>> kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] >>> kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 >>> kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 >>> __kmalloc+0x23c/0x350 mm/slub.c:3791 >>> kmalloc include/linux/slab.h:517 [inline] >>> vc_allocate+0x438/0x800 drivers/tty/vt/vt.c:787 >>> con_install+0x8c/0x640 drivers/tty/vt/vt.c:2876 >>> tty_driver_install_tty drivers/tty/tty_io.c:1224 [inline] >>> tty_init_dev+0x1b0/0x1020 drivers/tty/tty_io.c:1324 >>> tty_open_by_driver drivers/tty/tty_io.c:1959 [inline] >>> tty_open+0x15e9/0x2ea0 drivers/tty/tty_io.c:2007 >>> chrdev_open+0xc20/0xd90 fs/char_dev.c:417 >>> do_dentry_open+0xcc6/0x1430 fs/open.c:752 >>> vfs_open+0x1b7/0x2e0 fs/open.c:866 >>> do_last fs/namei.c:3379 [inline] >>> path_openat+0x460a/0x6520 fs/namei.c:3520 >>> do_filp_open+0x261/0x640 fs/namei.c:3554 >>> do_sys_open+0x624/0x960 fs/open.c:1059 >>> SYSC_open+0xab/0xc0 fs/open.c:1077 >>> SyS_open+0x54/0x80 fs/open.c:1072 >>> do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 >>> entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > > >>> Bytes 0-79 of 131 are uninitialized >>> ================================================================== > > > >>> --- >>> This bug 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 [email protected]. > > >>> syzbot will keep track of this bug report. See: >>> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with >>> syzbot. >>> syzbot can test patches for this bug, for details see: >>> https://goo.gl/tpsmEJ#testing-patches > > >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "syzkaller-bugs" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> To view this discussion on the web visit >>> >>> https://groups.google.com/d/msgid/syzkaller-bugs/000000000000da269e056c410efd%40google.com. >>> For more options, visit https://groups.google.com/d/optout.
