Messages in this thread | | | Date | Sat, 21 Oct 2023 11:49:56 -0700 | Subject | [syzbot] [kernel?] KMSAN: kernel-infoleak-after-free in copy_siginfo_to_user (2) | From | syzbot <> |
| |
Hello,
syzbot found the following issue on:
HEAD commit: dd72f9c7e512 Merge tag 'spi-fix-v6-6-rc4' of git://git.ker.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15fd7ae5680000 kernel config: https://syzkaller.appspot.com/x/.config?x=3f3af4cd712401d4 dashboard link: https://syzkaller.appspot.com/bug?extid=cfc08744435c4cf94a40 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/70e48b37a929/disk-dd72f9c7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/60aeb36b39dc/vmlinux-dd72f9c7.xz kernel image: https://storage.googleapis.com/syzbot-assets/71699a83a138/bzImage-dd72f9c7.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+cfc08744435c4cf94a40@syzkaller.appspotmail.com
===================================================== BUG: KMSAN: kernel-infoleak-after-free in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak-after-free in _copy_to_user+0xbc/0x100 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x100 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] copy_siginfo_to_user+0x40/0x130 kernel/signal.c:3362 x64_setup_rt_frame+0x1e74/0x2400 arch/x86/kernel/signal_64.c:197 setup_rt_frame arch/x86/kernel/signal.c:222 [inline] handle_signal arch/x86/kernel/signal.c:266 [inline] arch_do_signal_or_restart+0x626/0xca0 arch/x86/kernel/signal.c:311 exit_to_user_mode_loop+0xe8/0x320 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x163/0x220 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x2a/0x140 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Uninit was stored to memory at: copy_siginfo include/linux/signal.h:17 [inline] collect_signal kernel/signal.c:596 [inline] __dequeue_signal+0x548/0xa00 kernel/signal.c:625 dequeue_signal+0x14b/0xb10 kernel/signal.c:648 get_signal+0xc3f/0x2d10 kernel/signal.c:2772 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 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x2a/0x140 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Uninit was created at: slab_free_hook mm/slub.c:1770 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] kmem_cache_free+0x670/0x12a0 mm/slub.c:3831 __sigqueue_free kernel/signal.c:460 [inline] collect_signal kernel/signal.c:603 [inline] __dequeue_signal+0x998/0xa00 kernel/signal.c:625 dequeue_signal+0x14b/0xb10 kernel/signal.c:648 get_signal+0xc3f/0x2d10 kernel/signal.c:2772 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 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x2a/0x140 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Bytes 12-15 of 48 are uninitialized Memory access of size 48 starts at ffff88801301fdb0 Data copied to user address 000000c000e7bbf0
CPU: 0 PID: 5011 Comm: syz-fuzzer Not tainted 6.6.0-rc6-syzkaller-00043-gdd72f9c7e512 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 =====================================================
--- 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@googlegroups.com.
syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title
If you want to overwrite bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard)
If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with: #syz undup
| |