This is a note to let you know that I've just added the patch titled coresight: etm4x: Fix input validation for sysfs. to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the char-misc-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 2fe6899e36aa174abefd017887f9cfe0cb60c43a Mon Sep 17 00:00:00 2001 From: Mike Leach <mike.leach@xxxxxxxxxx> Date: Mon, 4 Nov 2019 11:12:42 -0700 Subject: coresight: etm4x: Fix input validation for sysfs. A number of issues are fixed relating to sysfs input validation:- 1) bb_ctrl_store() - incorrect compare of bit select field to absolute value. Reworked per ETMv4 specification. 2) seq_event_store() - incorrect mask value - register has two event values. 3) cyc_threshold_store() - must mask with max before checking min otherwise wrapped values can set illegal value below min. 4) res_ctrl_store() - update to mask off all res0 bits. Reviewed-by: Leo Yan <leo.yan@xxxxxxxxxx> Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx> Fixes: a77de2637c9eb ("coresight: etm4x: moving sysFS entries to a dedicated file") Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.9+ Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Link: https://lore.kernel.org/r/20191104181251.26732-6-mathieu.poirier@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- .../coresight/coresight-etm4x-sysfs.c | 21 ++++++++++++------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index b6984be0c515..cc8156318018 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -652,10 +652,13 @@ static ssize_t cyc_threshold_store(struct device *dev, if (kstrtoul(buf, 16, &val)) return -EINVAL; + + /* mask off max threshold before checking min value */ + val &= ETM_CYC_THRESHOLD_MASK; if (val < drvdata->ccitmin) return -EINVAL; - config->ccctlr = val & ETM_CYC_THRESHOLD_MASK; + config->ccctlr = val; return size; } static DEVICE_ATTR_RW(cyc_threshold); @@ -686,14 +689,16 @@ static ssize_t bb_ctrl_store(struct device *dev, return -EINVAL; if (!drvdata->nr_addr_cmp) return -EINVAL; + /* - * Bit[7:0] selects which address range comparator is used for - * branch broadcast control. + * Bit[8] controls include(1) / exclude(0), bits[0-7] select + * individual range comparators. If include then at least 1 + * range must be selected. */ - if (BMVAL(val, 0, 7) > drvdata->nr_addr_cmp) + if ((val & BIT(8)) && (BMVAL(val, 0, 7) == 0)) return -EINVAL; - config->bb_ctrl = val; + config->bb_ctrl = val & GENMASK(8, 0); return size; } static DEVICE_ATTR_RW(bb_ctrl); @@ -1324,8 +1329,8 @@ static ssize_t seq_event_store(struct device *dev, spin_lock(&drvdata->spinlock); idx = config->seq_idx; - /* RST, bits[7:0] */ - config->seq_ctrl[idx] = val & 0xFF; + /* Seq control has two masks B[15:8] F[7:0] */ + config->seq_ctrl[idx] = val & 0xFFFF; spin_unlock(&drvdata->spinlock); return size; } @@ -1580,7 +1585,7 @@ static ssize_t res_ctrl_store(struct device *dev, if (idx % 2 != 0) /* PAIRINV, bit[21] */ val &= ~BIT(21); - config->res_ctrl[idx] = val; + config->res_ctrl[idx] = val & GENMASK(21, 0); spin_unlock(&drvdata->spinlock); return size; } -- 2.23.0