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| author | Jakob Koschel <jakobkoschel@gmail.com> | 2022-01-27 17:44:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-02-16 14:56:33 +0300 |
| commit | ffe54289b02e9c732d6f04c8ebbe3b2d90d32118 (patch) | |
| tree | 8f853d9337ea86143128d744ce3c05ec303a4f61 /drivers/tty | |
| parent | f916181692cb5da7050ec0efbf96c915d8ebbbbc (diff) | |
| download | linux-ffe54289b02e9c732d6f04c8ebbe3b2d90d32118.tar.xz | |
vt_ioctl: fix array_index_nospec in vt_setactivate
commit 61cc70d9e8ef5b042d4ed87994d20100ec8896d9 upstream.
array_index_nospec ensures that an out-of-bounds value is set to zero
on the transient path. Decreasing the value by one afterwards causes
a transient integer underflow. vsa.console should be decreased first
and then sanitized with array_index_nospec.
Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh
Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU
Amsterdam.
Co-developed-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220127144406.3589293-1-jakobkoschel@gmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/vt/vt_ioctl.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c index 3639bb6dc372..e0714a9c9fd7 100644 --- a/drivers/tty/vt/vt_ioctl.c +++ b/drivers/tty/vt/vt_ioctl.c @@ -599,8 +599,8 @@ static int vt_setactivate(struct vt_setactivate __user *sa) if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES) return -ENXIO; - vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES + 1); vsa.console--; + vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES); console_lock(); ret = vc_allocate(vsa.console); if (ret) { |