If the core_pattern is set to "|" and any process segfaults then we get
a null pointer derefernce while trying to coredump. The call stack shows:
[ 108.212680] RIP: 0010:do_coredump+0x628/0x11c0
When the core_pattern has only "|" there is no use of trying the
coredump and we can check that while formating the corename and exit
with an error.
After this change I get:
[ 48.453756] format_corename failed
[ 48.453758] Aborting core
Fixes: 315c69261dd3 ("coredump: split pipe command whitespace before expanding template")
Reported-by: Matthew Ruffell <matthew.ruffell(a)canonical.com>
Cc: Paul Wise <pabs3(a)bonedaddy.net>
Cc: stable(a)vger.kernel.org
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee(a)gmail.com>
---
fs/coredump.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/coredump.c b/fs/coredump.c
index f8296a82d01d..408418e6aa13 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -211,6 +211,8 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm,
return -ENOMEM;
(*argv)[(*argc)++] = 0;
++pat_ptr;
+ if (!(*pat_ptr))
+ return -ENOMEM;
}
/* Repeat as long as we have more pattern to process and more output
--
2.11.0
From: Jason Gerecke <killertofu(a)gmail.com>
This reverts commit 15893fa40109f5e7c67eeb8da62267d0fdf0be9d.
The referenced commit broke pen and touch input for a variety of devices
such as the Cintiq Pro 32. Affected devices may appear to work normally
for a short amount of time, but eventually loose track of actual touch
state and can leave touch arbitration enabled which prevents the pen
from working. The commit is not itself required for any currently-available
Bluetooth device, and so we revert it to correct the behavior of broken
devices.
This breakage occurs due to a mismatch between the order of collections
and the order of usages on some devices. This commit tries to read the
contact count before processing events, but will fail if the contact
count does not occur prior to the first logical finger collection. This
is the case for devices like the Cintiq Pro 32 which place the contact
count at the very end of the report.
Without the contact count set, touches will only be partially processed.
The `wacom_wac_finger_slot` function will not open any slots since the
number of contacts seen is greater than the expectation of 0, but we will
still end up calling `input_mt_sync_frame` for each finger anyway. This
can cause problems for userspace separate from the issue currently taking
place in the kernel. Only once all of the individual finger collections
have been processed do we finally get to the enclosing collection which
contains the contact count. The value ends up being used for the *next*
report, however.
This delayed use of the contact count can cause the driver to loose track
of the actual touch state and believe that there are contacts down when
there aren't. This leaves touch arbitration enabled and prevents the pen
from working. It can also cause userspace to incorrectly treat single-
finger input as gestures.
Link: https://github.com/linuxwacom/input-wacom/issues/146
Signed-off-by: Jason Gerecke <jason.gerecke(a)wacom.com>
Reviewed-by: Aaron Armstrong Skomra <aaron.skomra(a)wacom.com>
Fixes: 15893fa40109 ("HID: wacom: generic: read the number of expected touches on a per collection basis")
Cc: stable(a)vger.kernel.org # 5.3+
---
drivers/hid/wacom_wac.c | 79 +++++++++--------------------------------
1 file changed, 16 insertions(+), 63 deletions(-)
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index d99a9d407671..96d00eba99c0 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2637,9 +2637,25 @@ static void wacom_wac_finger_pre_report(struct hid_device *hdev,
case HID_DG_TIPSWITCH:
hid_data->last_slot_field = equivalent_usage;
break;
+ case HID_DG_CONTACTCOUNT:
+ hid_data->cc_report = report->id;
+ hid_data->cc_index = i;
+ hid_data->cc_value_index = j;
+ break;
}
}
}
+
+ if (hid_data->cc_report != 0 &&
+ hid_data->cc_index >= 0) {
+ struct hid_field *field = report->field[hid_data->cc_index];
+ int value = field->value[hid_data->cc_value_index];
+ if (value)
+ hid_data->num_expected = value;
+ }
+ else {
+ hid_data->num_expected = wacom_wac->features.touch_max;
+ }
}
static void wacom_wac_finger_report(struct hid_device *hdev,
@@ -2649,7 +2665,6 @@ static void wacom_wac_finger_report(struct hid_device *hdev,
struct wacom_wac *wacom_wac = &wacom->wacom_wac;
struct input_dev *input = wacom_wac->touch_input;
unsigned touch_max = wacom_wac->features.touch_max;
- struct hid_data *hid_data = &wacom_wac->hid_data;
/* If more packets of data are expected, give us a chance to
* process them rather than immediately syncing a partial
@@ -2663,7 +2678,6 @@ static void wacom_wac_finger_report(struct hid_device *hdev,
input_sync(input);
wacom_wac->hid_data.num_received = 0;
- hid_data->num_expected = 0;
/* keep touch state for pen event */
wacom_wac->shared->touch_down = wacom_wac_finger_count_touches(wacom_wac);
@@ -2738,73 +2752,12 @@ static void wacom_report_events(struct hid_device *hdev,
}
}
-static void wacom_set_num_expected(struct hid_device *hdev,
- struct hid_report *report,
- int collection_index,
- struct hid_field *field,
- int field_index)
-{
- struct wacom *wacom = hid_get_drvdata(hdev);
- struct wacom_wac *wacom_wac = &wacom->wacom_wac;
- struct hid_data *hid_data = &wacom_wac->hid_data;
- unsigned int original_collection_level =
- hdev->collection[collection_index].level;
- bool end_collection = false;
- int i;
-
- if (hid_data->num_expected)
- return;
-
- // find the contact count value for this segment
- for (i = field_index; i < report->maxfield && !end_collection; i++) {
- struct hid_field *field = report->field[i];
- unsigned int field_level =
- hdev->collection[field->usage[0].collection_index].level;
- unsigned int j;
-
- if (field_level != original_collection_level)
- continue;
-
- for (j = 0; j < field->maxusage; j++) {
- struct hid_usage *usage = &field->usage[j];
-
- if (usage->collection_index != collection_index) {
- end_collection = true;
- break;
- }
- if (wacom_equivalent_usage(usage->hid) == HID_DG_CONTACTCOUNT) {
- hid_data->cc_report = report->id;
- hid_data->cc_index = i;
- hid_data->cc_value_index = j;
-
- if (hid_data->cc_report != 0 &&
- hid_data->cc_index >= 0) {
-
- struct hid_field *field =
- report->field[hid_data->cc_index];
- int value =
- field->value[hid_data->cc_value_index];
-
- if (value)
- hid_data->num_expected = value;
- }
- }
- }
- }
-
- if (hid_data->cc_report == 0 || hid_data->cc_index < 0)
- hid_data->num_expected = wacom_wac->features.touch_max;
-}
-
static int wacom_wac_collection(struct hid_device *hdev, struct hid_report *report,
int collection_index, struct hid_field *field,
int field_index)
{
struct wacom *wacom = hid_get_drvdata(hdev);
- if (WACOM_FINGER_FIELD(field))
- wacom_set_num_expected(hdev, report, collection_index, field,
- field_index);
wacom_report_events(hdev, report, collection_index, field_index);
/*
--
2.26.0
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 4b5142905d4ff58a4b93f7c8eaa7ba829c0a53c9 Mon Sep 17 00:00:00 2001
From: Nikos Tsironis <ntsironis(a)arrikto.com>
Date: Fri, 27 Mar 2020 16:01:08 +0200
Subject: [PATCH] dm clone: Fix handling of partial region discards
There is a bug in the way dm-clone handles discards, which can lead to
discarding the wrong blocks or trying to discard blocks beyond the end
of the device.
This could lead to data corruption, if the destination device indeed
discards the underlying blocks, i.e., if the discard operation results
in the original contents of a block to be lost.
The root of the problem is the code that calculates the range of regions
covered by a discard request and decides which regions to discard.
Since dm-clone handles the device in units of regions, we don't discard
parts of a region, only whole regions.
The range is calculated as:
rs = dm_sector_div_up(bio->bi_iter.bi_sector, clone->region_size);
re = bio_end_sector(bio) >> clone->region_shift;
, where 'rs' is the first region to discard and (re - rs) is the number
of regions to discard.
The bug manifests when we try to discard part of a single region, i.e.,
when we try to discard a block with size < region_size, and the discard
request both starts at an offset with respect to the beginning of that
region and ends before the end of the region.
The root cause is the following comparison:
if (rs == re)
// skip discard and complete original bio immediately
, which doesn't take into account that 'rs' might be greater than 're'.
Thus, we then issue a discard request for the wrong blocks, instead of
skipping the discard all together.
Fix the check to also take into account the above case, so we don't end
up discarding the wrong blocks.
Also, add some range checks to dm_clone_set_region_hydrated() and
dm_clone_cond_set_range(), which update dm-clone's region bitmap.
Note that the aforementioned bug doesn't cause invalid memory accesses,
because dm_clone_is_range_hydrated() returns True for this case, so the
checks are just precautionary.
Fixes: 7431b7835f55 ("dm: add clone target")
Cc: stable(a)vger.kernel.org # v5.4+
Signed-off-by: Nikos Tsironis <ntsironis(a)arrikto.com>
Signed-off-by: Mike Snitzer <snitzer(a)redhat.com>
diff --git a/drivers/md/dm-clone-metadata.c b/drivers/md/dm-clone-metadata.c
index c05b12110456..199e7af00858 100644
--- a/drivers/md/dm-clone-metadata.c
+++ b/drivers/md/dm-clone-metadata.c
@@ -850,6 +850,12 @@ int dm_clone_set_region_hydrated(struct dm_clone_metadata *cmd, unsigned long re
struct dirty_map *dmap;
unsigned long word, flags;
+ if (unlikely(region_nr >= cmd->nr_regions)) {
+ DMERR("Region %lu out of range (total number of regions %lu)",
+ region_nr, cmd->nr_regions);
+ return -ERANGE;
+ }
+
word = region_nr / BITS_PER_LONG;
spin_lock_irqsave(&cmd->bitmap_lock, flags);
@@ -879,6 +885,13 @@ int dm_clone_cond_set_range(struct dm_clone_metadata *cmd, unsigned long start,
struct dirty_map *dmap;
unsigned long word, region_nr;
+ if (unlikely(start >= cmd->nr_regions || (start + nr_regions) < start ||
+ (start + nr_regions) > cmd->nr_regions)) {
+ DMERR("Invalid region range: start %lu, nr_regions %lu (total number of regions %lu)",
+ start, nr_regions, cmd->nr_regions);
+ return -ERANGE;
+ }
+
spin_lock_irq(&cmd->bitmap_lock);
if (cmd->read_only) {
diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c
index d1e1b5b56b1b..022dddcad647 100644
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -293,10 +293,17 @@ static inline unsigned long bio_to_region(struct clone *clone, struct bio *bio)
/* Get the region range covered by the bio */
static void bio_region_range(struct clone *clone, struct bio *bio,
- unsigned long *rs, unsigned long *re)
+ unsigned long *rs, unsigned long *nr_regions)
{
+ unsigned long end;
+
*rs = dm_sector_div_up(bio->bi_iter.bi_sector, clone->region_size);
- *re = bio_end_sector(bio) >> clone->region_shift;
+ end = bio_end_sector(bio) >> clone->region_shift;
+
+ if (*rs >= end)
+ *nr_regions = 0;
+ else
+ *nr_regions = end - *rs;
}
/* Check whether a bio overwrites a region */
@@ -454,7 +461,7 @@ static void trim_bio(struct bio *bio, sector_t sector, unsigned int len)
static void complete_discard_bio(struct clone *clone, struct bio *bio, bool success)
{
- unsigned long rs, re;
+ unsigned long rs, nr_regions;
/*
* If the destination device supports discards, remap and trim the
@@ -463,9 +470,9 @@ static void complete_discard_bio(struct clone *clone, struct bio *bio, bool succ
*/
if (test_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags) && success) {
remap_to_dest(clone, bio);
- bio_region_range(clone, bio, &rs, &re);
+ bio_region_range(clone, bio, &rs, &nr_regions);
trim_bio(bio, rs << clone->region_shift,
- (re - rs) << clone->region_shift);
+ nr_regions << clone->region_shift);
generic_make_request(bio);
} else
bio_endio(bio);
@@ -473,12 +480,21 @@ static void complete_discard_bio(struct clone *clone, struct bio *bio, bool succ
static void process_discard_bio(struct clone *clone, struct bio *bio)
{
- unsigned long rs, re;
+ unsigned long rs, nr_regions;
- bio_region_range(clone, bio, &rs, &re);
- BUG_ON(re > clone->nr_regions);
+ bio_region_range(clone, bio, &rs, &nr_regions);
+ if (!nr_regions) {
+ bio_endio(bio);
+ return;
+ }
- if (unlikely(rs == re)) {
+ if (WARN_ON(rs >= clone->nr_regions || (rs + nr_regions) < rs ||
+ (rs + nr_regions) > clone->nr_regions)) {
+ DMERR("%s: Invalid range (%lu + %lu, total regions %lu) for discard (%llu + %u)",
+ clone_device_name(clone), rs, nr_regions,
+ clone->nr_regions,
+ (unsigned long long)bio->bi_iter.bi_sector,
+ bio_sectors(bio));
bio_endio(bio);
return;
}
@@ -487,7 +503,7 @@ static void process_discard_bio(struct clone *clone, struct bio *bio)
* The covered regions are already hydrated so we just need to pass
* down the discard.
*/
- if (dm_clone_is_range_hydrated(clone->cmd, rs, re - rs)) {
+ if (dm_clone_is_range_hydrated(clone->cmd, rs, nr_regions)) {
complete_discard_bio(clone, bio, true);
return;
}
@@ -1169,7 +1185,7 @@ static void process_deferred_discards(struct clone *clone)
int r = -EPERM;
struct bio *bio;
struct blk_plug plug;
- unsigned long rs, re;
+ unsigned long rs, nr_regions;
struct bio_list discards = BIO_EMPTY_LIST;
spin_lock_irq(&clone->lock);
@@ -1185,14 +1201,13 @@ static void process_deferred_discards(struct clone *clone)
/* Update the metadata */
bio_list_for_each(bio, &discards) {
- bio_region_range(clone, bio, &rs, &re);
+ bio_region_range(clone, bio, &rs, &nr_regions);
/*
* A discard request might cover regions that have been already
* hydrated. There is no need to update the metadata for these
* regions.
*/
- r = dm_clone_cond_set_range(clone->cmd, rs, re - rs);
-
+ r = dm_clone_cond_set_range(clone->cmd, rs, nr_regions);
if (unlikely(r))
break;
}