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authorIlpo Järvinen <ilpo.jarvinen@linux.intel.com>2023-04-11 19:45:32 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-04-20 14:11:33 +0200
commit2b3174c96696cde676393474f0e01d0d108462f5 (patch)
treea81a0ae7a4f0ff1c08bff6d31c0d621653f6e39a /drivers/tty
parentf91cf1a30255d81cf1d8992974ec0a9c0fd4a771 (diff)
n_gsm: Use array_index_nospec() with index that comes from userspace
dc.channel used for indexing comes directly from copy_from_user(). Use array_index_nospec() to mitigate speculative side-channel. Link: https://lore.kernel.org/linux-serial/64306d13.ONswMlyWlVKLGkKR%25lkp@intel.com/ Cc: stable <stable@kernel.org> Fixes: afe3154ba87e ("tty: n_gsm: add ioctl for DLC config via ldisc handle") Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Daniel Starke <daniel.starke@siemens.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230411164532.64175-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/n_gsm.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c42c8b89fd46..b411a26cc092 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -42,6 +42,7 @@
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/math.h>
+#include <linux/nospec.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/poll.h>
@@ -3717,8 +3718,8 @@ static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd,
struct gsm_config_ext ce;
struct gsm_dlci_config dc;
struct gsm_mux *gsm = tty->disc_data;
+ unsigned int base, addr;
struct gsm_dlci *dlci;
- unsigned int base;
switch (cmd) {
case GSMIOC_GETCONF:
@@ -3747,9 +3748,10 @@ static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd,
return -EFAULT;
if (dc.channel == 0 || dc.channel >= NUM_DLCI)
return -EINVAL;
- dlci = gsm->dlci[dc.channel];
+ addr = array_index_nospec(dc.channel, NUM_DLCI);
+ dlci = gsm->dlci[addr];
if (!dlci) {
- dlci = gsm_dlci_alloc(gsm, dc.channel);
+ dlci = gsm_dlci_alloc(gsm, addr);
if (!dlci)
return -ENOMEM;
}
@@ -3762,9 +3764,10 @@ static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd,
return -EFAULT;
if (dc.channel == 0 || dc.channel >= NUM_DLCI)
return -EINVAL;
- dlci = gsm->dlci[dc.channel];
+ addr = array_index_nospec(dc.channel, NUM_DLCI);
+ dlci = gsm->dlci[addr];
if (!dlci) {
- dlci = gsm_dlci_alloc(gsm, dc.channel);
+ dlci = gsm_dlci_alloc(gsm, addr);
if (!dlci)
return -ENOMEM;
}