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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-10-23 16:46:00 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-10-27 15:14:41 -0700 |
| commit | a50829479f58416a013a4ccca791336af3c584c7 (patch) | |
| tree | 74da0be0913dcd747df260a8432f2d8d8c708607 | |
| parent | 57a95b41869b8f0d1949c24df2a9dac1ca7082ee (diff) | |
| download | linux-a50829479f58416a013a4ccca791336af3c584c7.tar.gz | |
Input: gtco - fix potential out-of-bound access
parse_hid_report_descriptor() has a while (i < length) loop, which only guarantees that there's at least 1 byte in the buffer, but the loop body can read multiple bytes which causes out-of-bounds access. Reported-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
| -rw-r--r-- | drivers/input/tablet/gtco.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/input/tablet/gtco.c b/drivers/input/tablet/gtco.c index b796e891e2ee..4b8b9d7aa75e 100644 --- a/drivers/input/tablet/gtco.c +++ b/drivers/input/tablet/gtco.c @@ -230,13 +230,17 @@ static void parse_hid_report_descriptor(struct gtco *device, char * report, /* Walk this report and pull out the info we need */ while (i < length) { - prefix = report[i]; - - /* Skip over prefix */ - i++; + prefix = report[i++]; /* Determine data size and save the data in the proper variable */ - size = PREF_SIZE(prefix); + size = (1U << PREF_SIZE(prefix)) >> 1; + if (i + size > length) { + dev_err(ddev, + "Not enough data (need %d, have %d)\n", + i + size, length); + break; + } + switch (size) { case 1: data = report[i]; @@ -244,8 +248,7 @@ static void parse_hid_report_descriptor(struct gtco *device, char * report, case 2: data16 = get_unaligned_le16(&report[i]); break; - case 3: - size = 4; + case 4: data32 = get_unaligned_le32(&report[i]); break; } |