diff options
| author | Xiaomeng Tong | 2022-03-14 20:29:21 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2022-03-18 14:35:01 +0100 |
| commit | b31c41339f4f8a833cb9dc509f87aab6a159ffe4 (patch) | |
| tree | d7c026b19d3de366b23647c0150a687d550faadb /drivers/tty | |
| parent | f58c252e30cf74f68b0054293adc03b5923b9f0e (diff) | |
vt_ioctl: fix potential spectre v1 in VT_DISALLOCATE
In VT_ACTIVATE an almost identical code path has been patched
with array_index_nospec. In the VT_DISALLOCATE path, the arg is
the user input from a system call argument and lately used as a index
for vc_cons[index].d access, which can be reached through path like
vt_disallocate->vc_busy or vt_disallocate->vc_deallocate.
For consistency both code paths should have the same mitigations
applied. Also, the code style is adjusted as suggested by Jiri.
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Link: https://lore.kernel.org/r/20220314122921.31223-1-xiam0nd.tong@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/vt/vt_ioctl.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c index 58013698635f..8c685b501404 100644 --- a/drivers/tty/vt/vt_ioctl.c +++ b/drivers/tty/vt/vt_ioctl.c @@ -898,11 +898,13 @@ int vt_ioctl(struct tty_struct *tty, if (arg > MAX_NR_CONSOLES) return -ENXIO; - if (arg == 0) + if (arg == 0) { vt_disallocate_all(); - else - return vt_disallocate(--arg); - break; + break; + } + + arg = array_index_nospec(arg - 1, MAX_NR_CONSOLES); + return vt_disallocate(arg); case VT_RESIZE: { |