The kms paths keep a persistent map active to read and compare the cursor
buffer. These maps can race with each other in simple scenario where:
a) buffer "a" mapped for update
b) buffer "a" mapped for compare
c) do the compare
d) unmap "a" for compare
e) update the cursor
f) unmap "a" for update
At step "e" the buffer has been unmapped and the read contents is bogus.
Prevent unmapping of active read buffers by simply keeping a count of
how many paths have currently active maps and unmap only when the count
reaches 0.
v2: Update doc strings
Fixes: 485d98d472d5 ("drm/vmwgfx: Add support for CursorMob and CursorBypass 4")
Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list(a)broadcom.com>
Cc: dri-devel(a)lists.freedesktop.org
Cc: <stable(a)vger.kernel.org> # v5.19+
Signed-off-by: Zack Rusin <zack.rusin(a)broadcom.com>
---
drivers/gpu/drm/vmwgfx/vmwgfx_bo.c | 13 +++++++++++--
drivers/gpu/drm/vmwgfx/vmwgfx_bo.h | 3 +++
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index f42ebc4a7c22..a0e433fbcba6 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -360,6 +360,8 @@ void *vmw_bo_map_and_cache_size(struct vmw_bo *vbo, size_t size)
void *virtual;
int ret;
+ atomic_inc(&vbo->map_count);
+
virtual = ttm_kmap_obj_virtual(&vbo->map, ¬_used);
if (virtual)
return virtual;
@@ -383,11 +385,17 @@ void *vmw_bo_map_and_cache_size(struct vmw_bo *vbo, size_t size)
*/
void vmw_bo_unmap(struct vmw_bo *vbo)
{
+ int map_count;
+
if (vbo->map.bo == NULL)
return;
- ttm_bo_kunmap(&vbo->map);
- vbo->map.bo = NULL;
+ map_count = atomic_dec_return(&vbo->map_count);
+
+ if (!map_count) {
+ ttm_bo_kunmap(&vbo->map);
+ vbo->map.bo = NULL;
+ }
}
@@ -421,6 +429,7 @@ static int vmw_bo_init(struct vmw_private *dev_priv,
vmw_bo->tbo.priority = 3;
vmw_bo->res_tree = RB_ROOT;
xa_init(&vmw_bo->detached_resources);
+ atomic_set(&vmw_bo->map_count, 0);
params->size = ALIGN(params->size, PAGE_SIZE);
drm_gem_private_object_init(vdev, &vmw_bo->tbo.base, params->size);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
index 62b4342d5f7c..43b5439ec9f7 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
@@ -71,6 +71,8 @@ struct vmw_bo_params {
* @map: Kmap object for semi-persistent mappings
* @res_tree: RB tree of resources using this buffer object as a backing MOB
* @res_prios: Eviction priority counts for attached resources
+ * @map_count: The number of currently active maps. Will differ from the
+ * cpu_writers because it includes kernel maps.
* @cpu_writers: Number of synccpu write grabs. Protected by reservation when
* increased. May be decreased without reservation.
* @dx_query_ctx: DX context if this buffer object is used as a DX query MOB
@@ -90,6 +92,7 @@ struct vmw_bo {
u32 res_prios[TTM_MAX_BO_PRIORITY];
struct xarray detached_resources;
+ atomic_t map_count;
atomic_t cpu_writers;
/* Not ref-counted. Protected by binding_mutex */
struct vmw_resource *dx_query_ctx;
--
2.43.0
The patch titled
Subject: nilfs2: fix state management in error path of log writing function
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
nilfs2-fix-state-management-in-error-path-of-log-writing-function.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Subject: nilfs2: fix state management in error path of log writing function
Date: Wed, 14 Aug 2024 19:11:19 +0900
After commit a694291a6211 ("nilfs2: separate wait function from
nilfs_segctor_write") was applied, the log writing function
nilfs_segctor_do_construct() was able to issue I/O requests continuously
even if user data blocks were split into multiple logs across segments,
but two potential flaws were introduced in its error handling.
First, if nilfs_segctor_begin_construction() fails while creating the
second or subsequent logs, the log writing function returns without
calling nilfs_segctor_abort_construction(), so the writeback flag set on
pages/folios will remain uncleared. This causes page cache operations to
hang waiting for the writeback flag. For example,
truncate_inode_pages_final(), which is called via nilfs_evict_inode() when
an inode is evicted from memory, will hang.
Second, the NILFS_I_COLLECTED flag set on normal inodes remain uncleared.
As a result, if the next log write involves checkpoint creation, that's
fine, but if a partial log write is performed that does not, inodes with
NILFS_I_COLLECTED set are erroneously removed from the "sc_dirty_files"
list, and their data and b-tree blocks may not be written to the device,
corrupting the block mapping.
Fix these issues by uniformly calling nilfs_segctor_abort_construction()
on failure of each step in the loop in nilfs_segctor_do_construct(),
having it clean up logs and segment usages according to progress, and
correcting the conditions for calling nilfs_redirty_inodes() to ensure
that the NILFS_I_COLLECTED flag is cleared.
Link: https://lkml.kernel.org/r/20240814101119.4070-1-konishi.ryusuke@gmail.com
Fixes: a694291a6211 ("nilfs2: separate wait function from nilfs_segctor_write")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/nilfs2/segment.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
--- a/fs/nilfs2/segment.c~nilfs2-fix-state-management-in-error-path-of-log-writing-function
+++ a/fs/nilfs2/segment.c
@@ -1812,6 +1812,9 @@ static void nilfs_segctor_abort_construc
nilfs_abort_logs(&logs, ret ? : err);
list_splice_tail_init(&sci->sc_segbufs, &logs);
+ if (list_empty(&logs))
+ return; /* if the first segment buffer preparation failed */
+
nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
nilfs_free_incomplete_logs(&logs, nilfs);
@@ -2056,7 +2059,7 @@ static int nilfs_segctor_do_construct(st
err = nilfs_segctor_begin_construction(sci, nilfs);
if (unlikely(err))
- goto out;
+ goto failed;
/* Update time stamp */
sci->sc_seg_ctime = ktime_get_real_seconds();
@@ -2120,10 +2123,9 @@ static int nilfs_segctor_do_construct(st
return err;
failed_to_write:
- if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
- nilfs_redirty_inodes(&sci->sc_dirty_files);
-
failed:
+ if (mode == SC_LSEG_SR && nilfs_sc_cstage_get(sci) >= NILFS_ST_IFILE)
+ nilfs_redirty_inodes(&sci->sc_dirty_files);
if (nilfs_doing_gc())
nilfs_redirty_inodes(&sci->sc_gc_inodes);
nilfs_segctor_abort_construction(sci, nilfs, err);
_
Patches currently in -mm which might be from konishi.ryusuke(a)gmail.com are
nilfs2-protect-references-to-superblock-parameters-exposed-in-sysfs.patch
nilfs2-fix-missing-cleanup-on-rollforward-recovery-error.patch
nilfs2-fix-state-management-in-error-path-of-log-writing-function.patch
Dell All In One (AIO) models released after 2017 may use a backlight
controller board connected to an UART.
In DSDT this uart port will be defined as:
Name (_HID, "DELL0501")
Name (_CID, EisaId ("PNP0501")
The Dell OptiPlex 7760 AIO has an ACPI device for one if its UARTs with
the above _HID + _CID. Loading the dell-uart-backlight driver shows that
there actually is a backlight controller board attached to the UART,
which reports a firmware version of "G&MX01-V15".
But the backlight controller board does not actually control the backlight
brightness and the GPU's native backlight control method does work.
Add a quirk to use the GPU's native backlight control method on this model.
Fixes: 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver")
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2303936
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/acpi/video_detect.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index e509dcbf3090..674b9db7a1ef 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -823,6 +823,21 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
},
},
+ /*
+ * Dell AIO (All in Ones) which advertise an UART attached backlight
+ * controller board in their ACPI tables (and may even have one), but
+ * which need native backlight control nevertheless.
+ */
+ {
+ /* https://bugzilla.redhat.com/show_bug.cgi?id=2303936 */
+ .callback = video_detect_force_native,
+ /* Dell OptiPlex 7760 AIO */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7760 AIO"),
+ },
+ },
+
/*
* Models which have nvidia-ec-wmi support, but should not use it.
* Note this indicates a likely firmware bug on these models and should
--
2.46.0
The dell-uart-backlight driver supports backlight control on Dell All In
One (AIO) models using a backlight controller board connected to an UART.
In DSDT this uart port will be defined as:
Name (_HID, "DELL0501")
Name (_CID, EisaId ("PNP0501")
Now the first AIO has turned up which has not only the DSDT bits for this,
but also an actual controller attached to the UART, yet it is not using
this controller for backlight control.
Use the acpi_video_get_backlight_type() function from the ACPI video-detect
code to check if the dell-uart-backlight driver should actually be used.
This allows reusing the existing ACPI video-detect infra to override
the backlight control method on the commandline or with DMI quirks.
Fixes: 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/platform/x86/dell/Kconfig | 1 +
drivers/platform/x86/dell/dell-uart-backlight.c | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/drivers/platform/x86/dell/Kconfig b/drivers/platform/x86/dell/Kconfig
index f711c59fcf1b..11c2cb7d05b0 100644
--- a/drivers/platform/x86/dell/Kconfig
+++ b/drivers/platform/x86/dell/Kconfig
@@ -162,6 +162,7 @@ config DELL_SMO8800
config DELL_UART_BACKLIGHT
tristate "Dell AIO UART Backlight driver"
depends on ACPI
+ depends on ACPI_VIDEO
depends on BACKLIGHT_CLASS_DEVICE
depends on SERIAL_DEV_BUS
help
diff --git a/drivers/platform/x86/dell/dell-uart-backlight.c b/drivers/platform/x86/dell/dell-uart-backlight.c
index 87d2a20b4cb3..3995f90add45 100644
--- a/drivers/platform/x86/dell/dell-uart-backlight.c
+++ b/drivers/platform/x86/dell/dell-uart-backlight.c
@@ -20,6 +20,7 @@
#include <linux/string.h>
#include <linux/types.h>
#include <linux/wait.h>
+#include <acpi/video.h>
#include "../serdev_helpers.h"
/* The backlight controller must respond within 1 second */
@@ -332,10 +333,17 @@ struct serdev_device_driver dell_uart_bl_serdev_driver = {
static int dell_uart_bl_pdev_probe(struct platform_device *pdev)
{
+ enum acpi_backlight_type bl_type;
struct serdev_device *serdev;
struct device *ctrl_dev;
int ret;
+ bl_type = acpi_video_get_backlight_type();
+ if (bl_type != acpi_backlight_dell_uart) {
+ dev_dbg(&pdev->dev, "Not loading (ACPI backlight type = %d)\n", bl_type);
+ return -ENODEV;
+ }
+
ctrl_dev = get_serdev_controller("DELL0501", NULL, 0, "serial0");
if (IS_ERR(ctrl_dev))
return PTR_ERR(ctrl_dev);
--
2.46.0
Dell All In One (AIO) models released after 2017 use a backlight
controller board connected to an UART.
In DSDT this uart port will be defined as:
Name (_HID, "DELL0501")
Name (_CID, EisaId ("PNP0501")
Commit 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver")
has added support for this, but I neglected to tie this into
acpi_video_get_backlight_type().
Now the first AIO has turned up which has not only the DSDT bits for this,
but also an actual controller attached to the UART, yet it is not using
this controller for backlight control.
Add support to acpi_video_get_backlight_type() for a new dell_uart
backlight type. So that the existing infra to override the backlight
control method on the commandline or with DMI quirks can be used.
Fixes: 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede(a)redhat.com>
---
drivers/acpi/video_detect.c | 7 +++++++
include/acpi/video.h | 1 +
2 files changed, 8 insertions(+)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index c11cbe5b6eaa..e509dcbf3090 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -54,6 +54,8 @@ static void acpi_video_parse_cmdline(void)
acpi_backlight_cmdline = acpi_backlight_nvidia_wmi_ec;
if (!strcmp("apple_gmux", acpi_video_backlight_string))
acpi_backlight_cmdline = acpi_backlight_apple_gmux;
+ if (!strcmp("dell_uart", acpi_video_backlight_string))
+ acpi_backlight_cmdline = acpi_backlight_dell_uart;
if (!strcmp("none", acpi_video_backlight_string))
acpi_backlight_cmdline = acpi_backlight_none;
}
@@ -918,6 +920,7 @@ enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, bool *auto
static DEFINE_MUTEX(init_mutex);
static bool nvidia_wmi_ec_present;
static bool apple_gmux_present;
+ static bool dell_uart_present;
static bool native_available;
static bool init_done;
static long video_caps;
@@ -932,6 +935,7 @@ enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, bool *auto
&video_caps, NULL);
nvidia_wmi_ec_present = nvidia_wmi_ec_supported();
apple_gmux_present = apple_gmux_detect(NULL, NULL);
+ dell_uart_present = acpi_dev_present("DELL0501", NULL, -1);
init_done = true;
}
if (native)
@@ -962,6 +966,9 @@ enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, bool *auto
if (apple_gmux_present)
return acpi_backlight_apple_gmux;
+ if (dell_uart_present)
+ return acpi_backlight_dell_uart;
+
/* Use ACPI video if available, except when native should be preferred. */
if ((video_caps & ACPI_VIDEO_BACKLIGHT) &&
!(native_available && prefer_native_over_acpi_video()))
diff --git a/include/acpi/video.h b/include/acpi/video.h
index 3d538d4178ab..044c463138df 100644
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -50,6 +50,7 @@ enum acpi_backlight_type {
acpi_backlight_native,
acpi_backlight_nvidia_wmi_ec,
acpi_backlight_apple_gmux,
+ acpi_backlight_dell_uart,
};
#if IS_ENABLED(CONFIG_ACPI_VIDEO)
--
2.46.0
The patch below does not apply to the 6.1-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x f50733b45d865f91db90919f8311e2127ce5a0cb
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024081450-exploring-lego-5070@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
f50733b45d86 ("exec: Fix ToCToU between perm check and set-uid/gid usage")
e67fe63341b8 ("fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap")
9452e93e6dae ("fs: port privilege checking helpers to mnt_idmap")
f2d40141d5d9 ("fs: port inode_init_owner() to mnt_idmap")
4609e1f18e19 ("fs: port ->permission() to pass mnt_idmap")
13e83a4923be ("fs: port ->set_acl() to pass mnt_idmap")
77435322777d ("fs: port ->get_acl() to pass mnt_idmap")
011e2b717b1b ("fs: port ->tmpfile() to pass mnt_idmap")
5ebb29bee8d5 ("fs: port ->mknod() to pass mnt_idmap")
c54bd91e9eab ("fs: port ->mkdir() to pass mnt_idmap")
7a77db95511c ("fs: port ->symlink() to pass mnt_idmap")
6c960e68aaed ("fs: port ->create() to pass mnt_idmap")
b74d24f7a74f ("fs: port ->getattr() to pass mnt_idmap")
c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap")
abf08576afe3 ("fs: port vfs_*() helpers to struct mnt_idmap")
6022ec6ee2c3 ("Merge tag 'ntfs3_for_6.2' of https://github.com/Paragon-Software-Group/linux-ntfs3")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f50733b45d865f91db90919f8311e2127ce5a0cb Mon Sep 17 00:00:00 2001
From: Kees Cook <kees(a)kernel.org>
Date: Thu, 8 Aug 2024 11:39:08 -0700
Subject: [PATCH] exec: Fix ToCToU between perm check and set-uid/gid usage
When opening a file for exec via do_filp_open(), permission checking is
done against the file's metadata at that moment, and on success, a file
pointer is passed back. Much later in the execve() code path, the file
metadata (specifically mode, uid, and gid) is used to determine if/how
to set the uid and gid. However, those values may have changed since the
permissions check, meaning the execution may gain unintended privileges.
For example, if a file could change permissions from executable and not
set-id:
---------x 1 root root 16048 Aug 7 13:16 target
to set-id and non-executable:
---S------ 1 root root 16048 Aug 7 13:16 target
it is possible to gain root privileges when execution should have been
disallowed.
While this race condition is rare in real-world scenarios, it has been
observed (and proven exploitable) when package managers are updating
the setuid bits of installed programs. Such files start with being
world-executable but then are adjusted to be group-exec with a set-uid
bit. For example, "chmod o-x,u+s target" makes "target" executable only
by uid "root" and gid "cdrom", while also becoming setuid-root:
-rwxr-xr-x 1 root cdrom 16048 Aug 7 13:16 target
becomes:
-rwsr-xr-- 1 root cdrom 16048 Aug 7 13:16 target
But racing the chmod means users without group "cdrom" membership can
get the permission to execute "target" just before the chmod, and when
the chmod finishes, the exec reaches brpm_fill_uid(), and performs the
setuid to root, violating the expressed authorization of "only cdrom
group members can setuid to root".
Re-check that we still have execute permissions in case the metadata
has changed. It would be better to keep a copy from the perm-check time,
but until we can do that refactoring, the least-bad option is to do a
full inode_permission() call (under inode lock). It is understood that
this is safe against dead-locks, but hardly optimal.
Reported-by: Marco Vanotti <mvanotti(a)google.com>
Tested-by: Marco Vanotti <mvanotti(a)google.com>
Suggested-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: stable(a)vger.kernel.org
Cc: Eric Biederman <ebiederm(a)xmission.com>
Cc: Alexander Viro <viro(a)zeniv.linux.org.uk>
Cc: Christian Brauner <brauner(a)kernel.org>
Signed-off-by: Kees Cook <kees(a)kernel.org>
diff --git a/fs/exec.c b/fs/exec.c
index a126e3d1cacb..50e76cc633c4 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1692,6 +1692,7 @@ static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
unsigned int mode;
vfsuid_t vfsuid;
vfsgid_t vfsgid;
+ int err;
if (!mnt_may_suid(file->f_path.mnt))
return;
@@ -1708,12 +1709,17 @@ static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
/* Be careful if suid/sgid is set */
inode_lock(inode);
- /* reload atomically mode/uid/gid now that lock held */
+ /* Atomically reload and check mode/uid/gid now that lock held. */
mode = inode->i_mode;
vfsuid = i_uid_into_vfsuid(idmap, inode);
vfsgid = i_gid_into_vfsgid(idmap, inode);
+ err = inode_permission(idmap, inode, MAY_EXEC);
inode_unlock(inode);
+ /* Did the exec bit vanish out from under us? Give up. */
+ if (err)
+ return;
+
/* We ignore suid/sgid if there are no mappings for them in the ns */
if (!vfsuid_has_mapping(bprm->cred->user_ns, vfsuid) ||
!vfsgid_has_mapping(bprm->cred->user_ns, vfsgid))
Commit 97ab304ecd95 ("ASoC: topology: Fix references to freed memory")
is a problematic fix for issue in topology loading code, which was
cherry-picked to stable. It was later corrected in
0298f51652be ("ASoC: topology: Fix route memory corruption"), however to
apply cleanly e0e7bc2cbee9 ("ASoC: topology: Clean up route loading")
also needs to be applied.
Link: https://lore.kernel.org/linux-sound/ZrwUCnrtKQ61LWFS@sashalap/T/#mbfd273adf…
Should be applied to stable 6.1, 6.6, 6.9.
v2:
- Mention base commit
- Sign-off patches again, as those are cherrypicks
Amadeusz Sławiński (2):
ASoC: topology: Clean up route loading
ASoC: topology: Fix route memory corruption
sound/soc/soc-topology.c | 32 ++++++++------------------------
1 file changed, 8 insertions(+), 24 deletions(-)
--
2.34.1