`MFD_NOEXEC_SEAL` should remove the executable bits and set `F_SEAL_EXEC`
to prevent further modifications to the executable bits as per the comment
in the uapi header file:
not executable and sealed to prevent changing to executable
However, commit 105ff5339f498a ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
that introduced this feature made it so that `MFD_NOEXEC_SEAL` unsets
`F_SEAL_SEAL`, essentially acting as a superset of `MFD_ALLOW_SEALING`.
Nothing implies that it should be so, and indeed up until the second version
of the of the patchset[0] that introduced `MFD_EXEC` and `MFD_NOEXEC_SEAL`,
`F_SEAL_SEAL` was not removed, however, it was changed in the third revision
of the patchset[1] without a clear explanation.
This behaviour is surprising for application developers, there is no
documentation that would reveal that `MFD_NOEXEC_SEAL` has the additional
effect of `MFD_ALLOW_SEALING`. Additionally, combined with `vm.memfd_noexec=2`
it has the effect of making all memfds initially sealable.
So do not remove `F_SEAL_SEAL` when `MFD_NOEXEC_SEAL` is requested,
thereby returning to the pre-Linux 6.3 behaviour of only allowing
sealing when `MFD_ALLOW_SEALING` is specified.
Now, this is technically a uapi break. However, the damage is expected
to be minimal. To trigger user visible change, a program has to do the
following steps:
- create memfd:
- with `MFD_NOEXEC_SEAL`,
- without `MFD_ALLOW_SEALING`;
- try to add seals / check the seals.
But that seems unlikely to happen intentionally since this change
essentially reverts the kernel's behaviour to that of Linux <6.3,
so if a program worked correctly on those older kernels, it will
likely work correctly after this change.
I have used Debian Code Search and GitHub to try to find potential
breakages, and I could only find a single one. dbus-broker's
memfd_create() wrapper is aware of this implicit `MFD_ALLOW_SEALING`
behaviour, and tries to work around it[2]. This workaround will
break. Luckily, this only affects the test suite, it does not affect
the normal operations of dbus-broker. There is a PR with a fix[3].
I also carried out a smoke test by building a kernel with this change
and booting an Arch Linux system into GNOME and Plasma sessions.
There was also a previous attempt to address this peculiarity by
introducing a new flag[4].
[0]: https://lore.kernel.org/lkml/20220805222126.142525-3-jeffxu@google.com/
[1]: https://lore.kernel.org/lkml/20221202013404.163143-3-jeffxu@google.com/
[2]: https://github.com/bus1/dbus-broker/blob/9eb0b7e5826fc76cad7b025bc46f267d4a…
[3]: https://github.com/bus1/dbus-broker/pull/366
[4]: https://lore.kernel.org/lkml/20230714114753.170814-1-david@readahead.eu/
Cc: stable(a)vger.kernel.org
Signed-off-by: Barnabás Pőcze <pobrn(a)protonmail.com>
---
* v3: https://lore.kernel.org/linux-mm/20240611231409.3899809-1-jeffxu@chromium.o…
* v2: https://lore.kernel.org/linux-mm/20240524033933.135049-1-jeffxu@google.com/
* v1: https://lore.kernel.org/linux-mm/20240513191544.94754-1-pobrn@protonmail.co…
This fourth version returns to removing the inconsistency as opposed to documenting
its existence, with the same code change as v1 but with a somewhat extended commit
message. This is sent because I believe it is worth at least a try; it can be easily
reverted if bigger application breakages are discovered than initially imagined.
---
mm/memfd.c | 9 ++++-----
tools/testing/selftests/memfd/memfd_test.c | 2 +-
2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/mm/memfd.c b/mm/memfd.c
index 7d8d3ab3fa37..8b7f6afee21d 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -356,12 +356,11 @@ SYSCALL_DEFINE2(memfd_create,
inode->i_mode &= ~0111;
file_seals = memfd_file_seals_ptr(file);
- if (file_seals) {
- *file_seals &= ~F_SEAL_SEAL;
+ if (file_seals)
*file_seals |= F_SEAL_EXEC;
- }
- } else if (flags & MFD_ALLOW_SEALING) {
- /* MFD_EXEC and MFD_ALLOW_SEALING are set */
+ }
+
+ if (flags & MFD_ALLOW_SEALING) {
file_seals = memfd_file_seals_ptr(file);
if (file_seals)
*file_seals &= ~F_SEAL_SEAL;
diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c
index 95af2d78fd31..7b78329f65b6 100644
--- a/tools/testing/selftests/memfd/memfd_test.c
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -1151,7 +1151,7 @@ static void test_noexec_seal(void)
mfd_def_size,
MFD_CLOEXEC | MFD_NOEXEC_SEAL);
mfd_assert_mode(fd, 0666);
- mfd_assert_has_seals(fd, F_SEAL_EXEC);
+ mfd_assert_has_seals(fd, F_SEAL_SEAL | F_SEAL_EXEC);
mfd_fail_chmod(fd, 0777);
close(fd);
}
--
2.45.2
Disabling HPD polling from i915_hpd_poll_init_work() involves probing
all display connectors explicitly to account for lost hotplug
interrupts. On some platforms (mostly pre-ICL) with HDMI connectors the
I2C EDID bit-banging using udelay() triggers in turn the
workqueue: i915_hpd_poll_init_work [i915] hogged CPU for >10000us 4 times, consider switching to WQ_UNBOUND
warning.
Fix the above by scheduling i915_hpd_poll_init_work() on a WQ_UNBOUND
workqueue. It's ok to use a system WQ, since i915_hpd_poll_init_work()
is properly flushed in intel_hpd_cancel_work().
The connector probing from drm_mode_config::output_poll_work resulting
in the same warning is fixed by the next patch.
Cc: Tejun Heo <tj(a)kernel.org>
Cc: Heiner Kallweit <hkallweit1(a)gmail.com>
CC: stable(a)vger.kernel.org # 6.5
Suggested-by: Tejun Heo <tj(a)kernel.org>
Suggested-by: Heiner Kallweit <hkallweit1(a)gmail.com>
Reported-by: Heiner Kallweit <hkallweit1(a)gmail.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9245
Link: https://lore.kernel.org/all/f7e21caa-e98d-e5b5-932a-fe12d27fde9b@gmail.com
Signed-off-by: Imre Deak <imre.deak(a)intel.com>
---
drivers/gpu/drm/i915/display/intel_hotplug.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c
index e8562f6f8bb44..accc2fec562a0 100644
--- a/drivers/gpu/drm/i915/display/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
@@ -774,7 +774,7 @@ void intel_hpd_poll_enable(struct drm_i915_private *dev_priv)
* As well, there's no issue if we race here since we always reschedule
* this worker anyway
*/
- queue_work(dev_priv->unordered_wq,
+ queue_work(system_unbound_wq,
&dev_priv->display.hotplug.poll_init_work);
}
@@ -803,7 +803,7 @@ void intel_hpd_poll_disable(struct drm_i915_private *dev_priv)
return;
WRITE_ONCE(dev_priv->display.hotplug.poll_enabled, false);
- queue_work(dev_priv->unordered_wq,
+ queue_work(system_unbound_wq,
&dev_priv->display.hotplug.poll_init_work);
}
--
2.37.2
We notice some platforms set "snps,dis_u3_susphy_quirk" and
"snps,dis_u2_susphy_quirk" when they should not need to. Just make sure that
the GUSB3PIPECTL.SUSPENDENABLE and GUSB2PHYCFG.SUSPHY are clear during
initialization. The host initialization involved xhci. So the dwc3 needs to
implement the xhci_plat_priv->plat_start() for xhci to re-enable the suspend
bits.
Since there's a prerequisite patch to drivers/usb/host/xhci-plat.h that's not a
fix patch, this series should go on Greg's usb-testing branch instead of
usb-linus.
Thinh Nguyen (2):
usb: xhci-plat: Don't include xhci.h
usb: dwc3: core: Prevent phy suspend during init
drivers/usb/dwc3/core.c | 90 +++++++++++++++---------------------
drivers/usb/dwc3/core.h | 1 +
drivers/usb/dwc3/gadget.c | 2 +
drivers/usb/dwc3/host.c | 27 +++++++++++
drivers/usb/host/xhci-plat.h | 4 +-
5 files changed, 71 insertions(+), 53 deletions(-)
base-commit: 3d122e6d27e417a9fa91181922743df26b2cd679
--
2.28.0
On Tue, Mar 12, 2024 at 07:04:10AM -0400, Eric Hagberg wrote:
> On Thu, Mar 7, 2024 at 11:33 AM Steve Wahl <steve.wahl(a)hpe.com> wrote:
> > What Linux Distribution are you running on that machine? My guess
> > would be that this is not distro related; if you are running something
> > quite different from Pavin that would confirm this.
>
> Distro in use is Rocky 8, so it’s pretty clear not to be distro-specific.
>
> > I found an AMD based system to try to reproduce this on.
>
> yeah, it probably requires either a specific cpu or set or devices plus cpu
> to trigger… found that it also affects Dell R7625 servers in addition to
> the R6615s
I agree that it's likely the CPU or particular set of surrounding
devices that trigger the problem.
I have not succeeded in reproducing the problem yet. I tried an AMD
based system lent to me, but it's probably the wrong generation (AMD
EPYC 7251) and I didn't see the problem. I have a line on a system
that's more in line with the systems the bug was reported on that I
should be able to try tomorrow.
I would love to have some direction from the community at large on
this. The fact that nogbpages on the command line causes the same
problem without my patch suggests it's not bad code directly in my
patch, but something in the way kexec reacts to the resulting identity
map. One quick solution would be a kernel command line parameter to
select between the previous identity map creation behavior and the new
behavior. E.g. in addition to "nogbpages", we could have
"somegbpages" and "allgbpages" -- or gbpages=[all, some, none] with
nogbpages a synonym for backwards compatibility.
But I don't want to introduce a new command line parameter if the
actual problem can be understood and fixed. The question is how much
time do I have to persue a direct fix before some other action needs
to be taken?
Thanks,
--> Steve Wahl
--
Steve Wahl, Hewlett Packard Enterprise
Stuart Hayhurst has found that both at bootup and fullscreen VA-API video
is leading to black screens for around 1 second and kernel WARNING [1] traces
when calling dmub_psr_enable() with Parade 08-01 TCON.
These symptoms all go away with PSR-SU disabled for this TCON, so disable
it for now while DMUB traces [2] from the failure can be analyzed and the failure
state properly root caused.
Cc: stable(a)vger.kernel.org
Cc: Marc Rossi <Marc.Rossi(a)amd.com>
Cc: Hamza Mahfooz <Hamza.Mahfooz(a)amd.com>
Link: https://gitlab.freedesktop.org/drm/amd/uploads/a832dd515b571ee171b3e3b566e9… [1]
Link: https://gitlab.freedesktop.org/drm/amd/uploads/8f13ff3b00963c833e23e68aa811… [2]
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/2645
Signed-off-by: Mario Limonciello <mario.limonciello(a)amd.com>
---
---
drivers/gpu/drm/amd/display/modules/power/power_helpers.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
index e304e8435fb8..477289846a0a 100644
--- a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
+++ b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
@@ -841,6 +841,8 @@ bool is_psr_su_specific_panel(struct dc_link *link)
isPSRSUSupported = false;
else if (dpcd_caps->sink_dev_id_str[1] == 0x08 && dpcd_caps->sink_dev_id_str[0] == 0x03)
isPSRSUSupported = false;
+ else if (dpcd_caps->sink_dev_id_str[1] == 0x08 && dpcd_caps->sink_dev_id_str[0] == 0x01)
+ isPSRSUSupported = false;
else if (dpcd_caps->psr_info.force_psrsu_cap == 0x1)
isPSRSUSupported = true;
}
--
2.34.1
img_info->mhi_buf should be freed on error path in mhi_alloc_bhie_table().
This error case is rare but still needs to be fixed.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 3000f85b8f47 ("bus: mhi: core: Add support for basic PM operations")
Cc: stable(a)vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin(a)ispras.ru>
---
v2: add missing Cc: stable, as Greg Kroah-Hartman's bot reported
drivers/bus/mhi/host/boot.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
index edc0ec5a0933..738dcd11b66f 100644
--- a/drivers/bus/mhi/host/boot.c
+++ b/drivers/bus/mhi/host/boot.c
@@ -357,6 +357,7 @@ int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
for (--i, --mhi_buf; i >= 0; i--, mhi_buf--)
dma_free_coherent(mhi_cntrl->cntrl_dev, mhi_buf->len,
mhi_buf->buf, mhi_buf->dma_addr);
+ kfree(img_info->mhi_buf);
error_alloc_mhi_buf:
kfree(img_info);
--
2.39.2
Otherwise when the tracer changes syscall number to -1, the kernel fails
to initialize a0 with -ENOSYS and subsequently fails to return the error
code of the failed syscall to userspace. For example, it will break
strace syscall tampering.
Fixes: 52449c17bdd1 ("riscv: entry: set a0 = -ENOSYS only when syscall != -1")
Reported-by: "Dmitry V. Levin" <ldv(a)strace.io>
Reviewed-by: Björn Töpel <bjorn(a)rivosinc.com>
Cc: stable(a)vger.kernel.org
Signed-off-by: Celeste Liu <CoelacanthusHex(a)gmail.com>
---
arch/riscv/kernel/traps.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 05a16b1f0aee..51ebfd23e007 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -319,6 +319,7 @@ void do_trap_ecall_u(struct pt_regs *regs)
regs->epc += 4;
regs->orig_a0 = regs->a0;
+ regs->a0 = -ENOSYS;
riscv_v_vstate_discard(regs);
@@ -328,8 +329,7 @@ void do_trap_ecall_u(struct pt_regs *regs)
if (syscall >= 0 && syscall < NR_syscalls)
syscall_handler(regs, syscall);
- else if (syscall != -1)
- regs->a0 = -ENOSYS;
+
/*
* Ultimately, this value will get limited by KSTACK_OFFSET_MAX(),
* so the maximum stack offset is 1k bytes (10 bits).
--
2.45.2
This reverts commit ad6bcdad2b6724e113f191a12f859a9e8456b26d. I had
nak'd it, and Greg said on the thread that it links that he wasn't going
to take it either, especially since it's not his code or his tree, but
then, seemingly accidentally, it got pushed up some months later, in
what looks like a mistake, with no further discussion in the linked
thread. So revert it, since it's clearly not intended.
Fixes: ad6bcdad2b67 ("vmgenid: emit uevent when VMGENID updates")
Cc: stable(a)vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Link: https://lore.kernel.org/r/20230531095119.11202-2-bchalios@amazon.es
Signed-off-by: Jason A. Donenfeld <Jason(a)zx2c4.com>
---
drivers/virt/vmgenid.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c
index b67a28da4702..a1c467a0e9f7 100644
--- a/drivers/virt/vmgenid.c
+++ b/drivers/virt/vmgenid.c
@@ -68,7 +68,6 @@ static int vmgenid_add(struct acpi_device *device)
static void vmgenid_notify(struct acpi_device *device, u32 event)
{
struct vmgenid_state *state = acpi_driver_data(device);
- char *envp[] = { "NEW_VMGENID=1", NULL };
u8 old_id[VMGENID_SIZE];
memcpy(old_id, state->this_id, sizeof(old_id));
@@ -76,7 +75,6 @@ static void vmgenid_notify(struct acpi_device *device, u32 event)
if (!memcmp(old_id, state->this_id, sizeof(old_id)))
return;
add_vmfork_randomness(state->this_id, sizeof(state->this_id));
- kobject_uevent_env(&device->dev.kobj, KOBJ_CHANGE, envp);
}
static const struct acpi_device_id vmgenid_ids[] = {
--
2.44.0