* Re: [PATCH v3 1/2] phy: qcom: edp: Add eDP/DP mode switch support
From: Yongxing Mou @ 2026-04-20 12:48 UTC (permalink / raw)
To: Konrad Dybcio, Vinod Koul, Neil Armstrong, Stephen Boyd,
Bjorn Andersson
Cc: linux-arm-msm, linux-phy, linux-kernel, stable
In-Reply-To: <245f4589-d7ca-4d6b-8162-a86972752bd8@oss.qualcomm.com>
On 4/16/2026 5:34 PM, Konrad Dybcio wrote:
> On 3/2/26 9:28 AM, Yongxing Mou wrote:
>> The eDP PHY supports both eDP&DP modes, each requires a different table.
>> The current driver doesn't fully support every combo PHY mode and use
>> either the eDP or DP table when enable the platform. In addition, some
>> platforms mismatch between the mode and the table where DP mode uses
>> the eDP table or eDP mode use the DP table.
>>
>> Clean up and correct the tables for currently supported platforms based on
>> the HPG specification.
>>
>> Here lists the tables can be reused across current platforms.
>> DP mode：
>> -sa8775p/sc7280/sc8280xp/x1e80100
>> -glymur
>> eDP mode(low vdiff):
>> -glymur/sa8775p/sc8280xp/x1e80100
>> -sc7280
>>
>> Cc: stable@vger.kernel.org
>> Fixes: f199223cb490 ("phy: qcom: Introduce new eDP PHY driver")
>> Signed-off-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com>
>> ---
>
> I went through everything and all the sequences are OK.
>
> SC8180X will need changes, but it's already incorrect so this
> doesn't necessarily affect it
>
> Thanks!
>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
>
> Konrad
Thanks here.. I didn’t notice before that SC8180X is different from
SC7280, and will correct it in the next version.
^ permalink raw reply
* Re: [PATCH v3 1/2] phy: qcom: edp: Add eDP/DP mode switch support
From: Konrad Dybcio @ 2026-04-20 12:49 UTC (permalink / raw)
To: Yongxing Mou, Vinod Koul, Neil Armstrong, Stephen Boyd,
Bjorn Andersson
Cc: linux-arm-msm, linux-phy, linux-kernel, stable
In-Reply-To: <12e8a8de-49b8-463a-8b88-2cbbf1ab901c@oss.qualcomm.com>
On 4/20/26 2:48 PM, Yongxing Mou wrote:
>
>
> On 4/16/2026 5:34 PM, Konrad Dybcio wrote:
>> On 3/2/26 9:28 AM, Yongxing Mou wrote:
>>> The eDP PHY supports both eDP&DP modes, each requires a different table.
>>> The current driver doesn't fully support every combo PHY mode and use
>>> either the eDP or DP table when enable the platform. In addition, some
>>> platforms mismatch between the mode and the table where DP mode uses
>>> the eDP table or eDP mode use the DP table.
>>>
>>> Clean up and correct the tables for currently supported platforms based on
>>> the HPG specification.
>>>
>>> Here lists the tables can be reused across current platforms.
>>> DP mode：
>>> -sa8775p/sc7280/sc8280xp/x1e80100
>>> -glymur
>>> eDP mode(low vdiff):
>>> -glymur/sa8775p/sc8280xp/x1e80100
>>> -sc7280
>>>
>>> Cc: stable@vger.kernel.org
>>> Fixes: f199223cb490 ("phy: qcom: Introduce new eDP PHY driver")
>>> Signed-off-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com>
>>> ---
>>
>> I went through everything and all the sequences are OK.
>>
>> SC8180X will need changes, but it's already incorrect so this
>> doesn't necessarily affect it
>>
>> Thanks!
>>
>> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
>>
>> Konrad
> Thanks here.. I didn’t notice before that SC8180X is different from SC7280, and will correct it in the next version.
Please make it another patch on top of these two, so that we don't have
to re-validate the existing diff
Konrad
^ permalink raw reply
* FAILED: patch "[PATCH] scripts: generate_rust_analyzer.py: define scripts" failed to apply to 7.0-stable tree
From: gregkh @ 2026-04-20 12:56 UTC (permalink / raw)
To: tamird, daniel.almeida, me, tmgross; +Cc: stable
The patch below does not apply to the 7.0-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@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-7.0.y
git checkout FETCH_HEAD
git cherry-pick -x 36c619f6bd793493294becb10a02fea370b67a91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042045-drool-wheat-4281@gregkh' --subject-prefix 'PATCH 7.0.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 36c619f6bd793493294becb10a02fea370b67a91 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@kernel.org>
Date: Thu, 22 Jan 2026 11:53:28 -0500
Subject: [PATCH] scripts: generate_rust_analyzer.py: define scripts
Add IDE support for host-side scripts written in Rust. This support has
been missing since these scripts were initially added in commit
9a8ff24ce584 ("scripts: add `generate_rust_target.rs`"), thus add it.
Change the existing instance of extension stripping to
`pathlib.Path.stem` to maintain code consistency.
Fixes: 9a8ff24ce584 ("scripts: add `generate_rust_target.rs`")
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://patch.msgid.link/20260122-rust-analyzer-scripts-v1-1-ff6ba278170e@kernel.org
Signed-off-by: Tamir Duberstein <tamird@kernel.org>
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 7becc2698c14..38e834bd209e 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -299,6 +299,18 @@ def generate_crates(
"kernel", [core, macros, build_error, pin_init, ffi, bindings, uapi]
)
+ scripts = srctree / "scripts"
+ makefile = (scripts / "Makefile").read_text()
+ for path in scripts.glob("*.rs"):
+ name = path.stem
+ if f"{name}-rust" not in makefile:
+ continue
+ append_crate(
+ name,
+ path,
+ [std],
+ )
+
def is_root_crate(build_file: pathlib.Path, target: str) -> bool:
try:
return f"{target}.o" in open(build_file).read()
@@ -316,7 +328,7 @@ def generate_crates(
for folder in extra_dirs:
for path in folder.rglob("*.rs"):
logging.info("Checking %s", path)
- name = path.name.replace(".rs", "")
+ name = path.stem
# Skip those that are not crate roots.
if not is_root_crate(path.parent / "Makefile", name) and \
^ permalink raw reply related
* FAILED: patch "[PATCH] scripts: generate_rust_analyzer.py: define scripts" failed to apply to 6.19-stable tree
From: gregkh @ 2026-04-20 12:56 UTC (permalink / raw)
To: tamird, daniel.almeida, me, tmgross; +Cc: stable
The patch below does not apply to the 6.19-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@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-6.19.y
git checkout FETCH_HEAD
git cherry-pick -x 36c619f6bd793493294becb10a02fea370b67a91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042045-fountain-ebony-21f7@gregkh' --subject-prefix 'PATCH 6.19.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 36c619f6bd793493294becb10a02fea370b67a91 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@kernel.org>
Date: Thu, 22 Jan 2026 11:53:28 -0500
Subject: [PATCH] scripts: generate_rust_analyzer.py: define scripts
Add IDE support for host-side scripts written in Rust. This support has
been missing since these scripts were initially added in commit
9a8ff24ce584 ("scripts: add `generate_rust_target.rs`"), thus add it.
Change the existing instance of extension stripping to
`pathlib.Path.stem` to maintain code consistency.
Fixes: 9a8ff24ce584 ("scripts: add `generate_rust_target.rs`")
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://patch.msgid.link/20260122-rust-analyzer-scripts-v1-1-ff6ba278170e@kernel.org
Signed-off-by: Tamir Duberstein <tamird@kernel.org>
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 7becc2698c14..38e834bd209e 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -299,6 +299,18 @@ def generate_crates(
"kernel", [core, macros, build_error, pin_init, ffi, bindings, uapi]
)
+ scripts = srctree / "scripts"
+ makefile = (scripts / "Makefile").read_text()
+ for path in scripts.glob("*.rs"):
+ name = path.stem
+ if f"{name}-rust" not in makefile:
+ continue
+ append_crate(
+ name,
+ path,
+ [std],
+ )
+
def is_root_crate(build_file: pathlib.Path, target: str) -> bool:
try:
return f"{target}.o" in open(build_file).read()
@@ -316,7 +328,7 @@ def generate_crates(
for folder in extra_dirs:
for path in folder.rglob("*.rs"):
logging.info("Checking %s", path)
- name = path.name.replace(".rs", "")
+ name = path.stem
# Skip those that are not crate roots.
if not is_root_crate(path.parent / "Makefile", name) and \
^ permalink raw reply related
* FAILED: patch "[PATCH] scripts: generate_rust_analyzer.py: define scripts" failed to apply to 6.12-stable tree
From: gregkh @ 2026-04-20 12:56 UTC (permalink / raw)
To: tamird, daniel.almeida, me, tmgross; +Cc: stable
The patch below does not apply to the 6.12-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@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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 36c619f6bd793493294becb10a02fea370b67a91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042046-anime-babied-0905@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 36c619f6bd793493294becb10a02fea370b67a91 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@kernel.org>
Date: Thu, 22 Jan 2026 11:53:28 -0500
Subject: [PATCH] scripts: generate_rust_analyzer.py: define scripts
Add IDE support for host-side scripts written in Rust. This support has
been missing since these scripts were initially added in commit
9a8ff24ce584 ("scripts: add `generate_rust_target.rs`"), thus add it.
Change the existing instance of extension stripping to
`pathlib.Path.stem` to maintain code consistency.
Fixes: 9a8ff24ce584 ("scripts: add `generate_rust_target.rs`")
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://patch.msgid.link/20260122-rust-analyzer-scripts-v1-1-ff6ba278170e@kernel.org
Signed-off-by: Tamir Duberstein <tamird@kernel.org>
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 7becc2698c14..38e834bd209e 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -299,6 +299,18 @@ def generate_crates(
"kernel", [core, macros, build_error, pin_init, ffi, bindings, uapi]
)
+ scripts = srctree / "scripts"
+ makefile = (scripts / "Makefile").read_text()
+ for path in scripts.glob("*.rs"):
+ name = path.stem
+ if f"{name}-rust" not in makefile:
+ continue
+ append_crate(
+ name,
+ path,
+ [std],
+ )
+
def is_root_crate(build_file: pathlib.Path, target: str) -> bool:
try:
return f"{target}.o" in open(build_file).read()
@@ -316,7 +328,7 @@ def generate_crates(
for folder in extra_dirs:
for path in folder.rglob("*.rs"):
logging.info("Checking %s", path)
- name = path.name.replace(".rs", "")
+ name = path.stem
# Skip those that are not crate roots.
if not is_root_crate(path.parent / "Makefile", name) and \
^ permalink raw reply related
* FAILED: patch "[PATCH] scripts: generate_rust_analyzer.py: define scripts" failed to apply to 6.18-stable tree
From: gregkh @ 2026-04-20 12:56 UTC (permalink / raw)
To: tamird, daniel.almeida, me, tmgross; +Cc: stable
The patch below does not apply to the 6.18-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@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-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 36c619f6bd793493294becb10a02fea370b67a91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042046-underfeed-riding-d661@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 36c619f6bd793493294becb10a02fea370b67a91 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@kernel.org>
Date: Thu, 22 Jan 2026 11:53:28 -0500
Subject: [PATCH] scripts: generate_rust_analyzer.py: define scripts
Add IDE support for host-side scripts written in Rust. This support has
been missing since these scripts were initially added in commit
9a8ff24ce584 ("scripts: add `generate_rust_target.rs`"), thus add it.
Change the existing instance of extension stripping to
`pathlib.Path.stem` to maintain code consistency.
Fixes: 9a8ff24ce584 ("scripts: add `generate_rust_target.rs`")
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://patch.msgid.link/20260122-rust-analyzer-scripts-v1-1-ff6ba278170e@kernel.org
Signed-off-by: Tamir Duberstein <tamird@kernel.org>
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 7becc2698c14..38e834bd209e 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -299,6 +299,18 @@ def generate_crates(
"kernel", [core, macros, build_error, pin_init, ffi, bindings, uapi]
)
+ scripts = srctree / "scripts"
+ makefile = (scripts / "Makefile").read_text()
+ for path in scripts.glob("*.rs"):
+ name = path.stem
+ if f"{name}-rust" not in makefile:
+ continue
+ append_crate(
+ name,
+ path,
+ [std],
+ )
+
def is_root_crate(build_file: pathlib.Path, target: str) -> bool:
try:
return f"{target}.o" in open(build_file).read()
@@ -316,7 +328,7 @@ def generate_crates(
for folder in extra_dirs:
for path in folder.rglob("*.rs"):
logging.info("Checking %s", path)
- name = path.name.replace(".rs", "")
+ name = path.stem
# Skip those that are not crate roots.
if not is_root_crate(path.parent / "Makefile", name) and \
^ permalink raw reply related
* FAILED: patch "[PATCH] scripts: generate_rust_analyzer.py: define scripts" failed to apply to 6.1-stable tree
From: gregkh @ 2026-04-20 12:56 UTC (permalink / raw)
To: tamird, daniel.almeida, me, tmgross; +Cc: stable
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@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 36c619f6bd793493294becb10a02fea370b67a91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042047-kissable-reboot-f1bc@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 36c619f6bd793493294becb10a02fea370b67a91 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@kernel.org>
Date: Thu, 22 Jan 2026 11:53:28 -0500
Subject: [PATCH] scripts: generate_rust_analyzer.py: define scripts
Add IDE support for host-side scripts written in Rust. This support has
been missing since these scripts were initially added in commit
9a8ff24ce584 ("scripts: add `generate_rust_target.rs`"), thus add it.
Change the existing instance of extension stripping to
`pathlib.Path.stem` to maintain code consistency.
Fixes: 9a8ff24ce584 ("scripts: add `generate_rust_target.rs`")
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://patch.msgid.link/20260122-rust-analyzer-scripts-v1-1-ff6ba278170e@kernel.org
Signed-off-by: Tamir Duberstein <tamird@kernel.org>
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 7becc2698c14..38e834bd209e 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -299,6 +299,18 @@ def generate_crates(
"kernel", [core, macros, build_error, pin_init, ffi, bindings, uapi]
)
+ scripts = srctree / "scripts"
+ makefile = (scripts / "Makefile").read_text()
+ for path in scripts.glob("*.rs"):
+ name = path.stem
+ if f"{name}-rust" not in makefile:
+ continue
+ append_crate(
+ name,
+ path,
+ [std],
+ )
+
def is_root_crate(build_file: pathlib.Path, target: str) -> bool:
try:
return f"{target}.o" in open(build_file).read()
@@ -316,7 +328,7 @@ def generate_crates(
for folder in extra_dirs:
for path in folder.rglob("*.rs"):
logging.info("Checking %s", path)
- name = path.name.replace(".rs", "")
+ name = path.stem
# Skip those that are not crate roots.
if not is_root_crate(path.parent / "Makefile", name) and \
^ permalink raw reply related
* FAILED: patch "[PATCH] scripts: generate_rust_analyzer.py: define scripts" failed to apply to 6.6-stable tree
From: gregkh @ 2026-04-20 12:56 UTC (permalink / raw)
To: tamird, daniel.almeida, me, tmgross; +Cc: stable
The patch below does not apply to the 6.6-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@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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 36c619f6bd793493294becb10a02fea370b67a91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042047-drizzly-oblivious-029f@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 36c619f6bd793493294becb10a02fea370b67a91 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@kernel.org>
Date: Thu, 22 Jan 2026 11:53:28 -0500
Subject: [PATCH] scripts: generate_rust_analyzer.py: define scripts
Add IDE support for host-side scripts written in Rust. This support has
been missing since these scripts were initially added in commit
9a8ff24ce584 ("scripts: add `generate_rust_target.rs`"), thus add it.
Change the existing instance of extension stripping to
`pathlib.Path.stem` to maintain code consistency.
Fixes: 9a8ff24ce584 ("scripts: add `generate_rust_target.rs`")
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://patch.msgid.link/20260122-rust-analyzer-scripts-v1-1-ff6ba278170e@kernel.org
Signed-off-by: Tamir Duberstein <tamird@kernel.org>
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 7becc2698c14..38e834bd209e 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -299,6 +299,18 @@ def generate_crates(
"kernel", [core, macros, build_error, pin_init, ffi, bindings, uapi]
)
+ scripts = srctree / "scripts"
+ makefile = (scripts / "Makefile").read_text()
+ for path in scripts.glob("*.rs"):
+ name = path.stem
+ if f"{name}-rust" not in makefile:
+ continue
+ append_crate(
+ name,
+ path,
+ [std],
+ )
+
def is_root_crate(build_file: pathlib.Path, target: str) -> bool:
try:
return f"{target}.o" in open(build_file).read()
@@ -316,7 +328,7 @@ def generate_crates(
for folder in extra_dirs:
for path in folder.rglob("*.rs"):
logging.info("Checking %s", path)
- name = path.name.replace(".rs", "")
+ name = path.stem
# Skip those that are not crate roots.
if not is_root_crate(path.parent / "Makefile", name) and \
^ permalink raw reply related
* [PATCH] pnfs/flexfiles: reject zero version_count in GETDEVICEINFO
From: Junrui Luo @ 2026-04-20 13:01 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker, Weston Andros Adamson, Tao Peng,
Tom Haynes
Cc: linux-nfs, linux-kernel, Yuhao Jiang, stable, Junrui Luo
nfs4_ff_alloc_deviceid_node() parses the flexfiles device address from
a GETDEVICEINFO response and passes version_count to kzalloc_objs()
without validating it is non-zero. A zero count makes kzalloc_objs()
return ZERO_SIZE_PTR, which passes the NULL check.
This leads to a NULL pointer dereference when
nfs4_ff_layout_ds_version() later accesses ds_versions[0] through the
ZERO_SIZE_PTR.
Fix by rejecting version_count == 0 before the allocation.
Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
---
fs/nfs/flexfilelayout/flexfilelayoutdev.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
index c40395ae0814..d5aa6bf3ecbc 100644
--- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c
+++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
@@ -99,6 +99,11 @@ nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
version_count = be32_to_cpup(p);
dprintk("%s: version count %d\n", __func__, version_count);
+ if (version_count == 0) {
+ ret = -EINVAL;
+ goto out_err_drain_dsaddrs;
+ }
+
ds_versions = kzalloc_objs(struct nfs4_ff_ds_version, version_count,
gfp_flags);
if (!ds_versions)
---
base-commit: 7aaa8047eafd0bd628065b15757d9b48c5f9c07d
change-id: 20260420-fixes-9f910b7b5cde
Best regards,
--
Junrui Luo <moonafterrain@outlook.com>
^ permalink raw reply related
* Re: [PATCH] vmalloc: fix buffer overflow in vrealloc_node_align()
From: Harry Yoo (Oracle) @ 2026-04-20 13:04 UTC (permalink / raw)
To: Marco Elver
Cc: Vlastimil Babka, Andrew Morton, Uladzislau Rezki, linux-mm,
linux-kernel, kasan-dev, Vitaly Wool, stable
In-Reply-To: <20260420114805.3572606-2-elver@google.com>
On Mon, Apr 20, 2026 at 01:47:26PM +0200, Marco Elver wrote:
> Commit 4c5d3365882d ("mm/vmalloc: allow to set node and align in
> vrealloc") added the ability to force a new allocation if the current
> pointer is on the wrong NUMA node, or if an alignment constraint is not
> met, even if the user is shrinking the allocation.
>
> On this path (need_realloc), the code allocates a new object of 'size'
> bytes and then memcpy()s 'old_size' bytes into it. If the request is to
> shrink the object (size < old_size), this results in an out-of-bounds
> write on the new buffer.
>
> Fix this by bounding the copy length by the new allocation size.
>
> Fixes: 4c5d3365882d ("mm/vmalloc: allow to set node and align in vrealloc")
> Cc: <stable@vger.kernel.org>
> Reported-by: Harry Yoo (Oracle) <harry@kernel.org>
> Signed-off-by: Marco Elver <elver@google.com>
> ---
Looks good to me,
Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org>
Thanks a lot for fixing it!
> mm/vmalloc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 61caa55a4402..8b1124158f54 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -4361,7 +4361,7 @@ void *vrealloc_node_align_noprof(const void *p, size_t size, unsigned long align
> return NULL;
>
> if (p) {
> - memcpy(n, p, old_size);
> + memcpy(n, p, min(size, old_size));
> vfree(p);
> }
>
> --
> 2.54.0.rc1.513.gad8abe7a5a-goog
--
Cheers,
Harry / Hyeonggon
^ permalink raw reply
* FAILED: patch "[PATCH] ocfs2: fix possible deadlock between unlink and" failed to apply to 5.15-stable tree
From: gregkh @ 2026-04-20 13:05 UTC (permalink / raw)
To: joseph.qi, akpm, gechangwei, heming.zhao, jiangqi903, jlbec,
junxiao.bi, mark, piaojun, stable
Cc: stable
The patch below does not apply to the 5.15-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@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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x b02da26a992db0c0e2559acbda0fc48d4a2fd337
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042002-rumbling-plunder-40f1@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b02da26a992db0c0e2559acbda0fc48d4a2fd337 Mon Sep 17 00:00:00 2001
From: Joseph Qi <joseph.qi@linux.alibaba.com>
Date: Fri, 6 Mar 2026 11:22:11 +0800
Subject: [PATCH] ocfs2: fix possible deadlock between unlink and
dio_end_io_write
ocfs2_unlink takes orphan dir inode_lock first and then ip_alloc_sem,
while in ocfs2_dio_end_io_write, it acquires these locks in reverse order.
This creates an ABBA lock ordering violation on lock classes
ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] and
ocfs2_file_ip_alloc_sem_key.
Lock Chain #0 (orphan dir inode_lock -> ip_alloc_sem):
ocfs2_unlink
ocfs2_prepare_orphan_dir
ocfs2_lookup_lock_orphan_dir
inode_lock(orphan_dir_inode) <- lock A
__ocfs2_prepare_orphan_dir
ocfs2_prepare_dir_for_insert
ocfs2_extend_dir
ocfs2_expand_inline_dir
down_write(&oi->ip_alloc_sem) <- Lock B
Lock Chain #1 (ip_alloc_sem -> orphan dir inode_lock):
ocfs2_dio_end_io_write
down_write(&oi->ip_alloc_sem) <- Lock B
ocfs2_del_inode_from_orphan()
inode_lock(orphan_dir_inode) <- Lock A
Deadlock Scenario:
CPU0 (unlink) CPU1 (dio_end_io_write)
------ ------
inode_lock(orphan_dir_inode)
down_write(ip_alloc_sem)
down_write(ip_alloc_sem)
inode_lock(orphan_dir_inode)
Since ip_alloc_sem is to protect allocation changes, which is unrelated
with operations in ocfs2_del_inode_from_orphan. So move
ocfs2_del_inode_from_orphan out of ip_alloc_sem to fix the deadlock.
Link: https://lkml.kernel.org/r/20260306032211.1016452-1-joseph.qi@linux.alibaba.com
Reported-by: syzbot+67b90111784a3eac8c04@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=67b90111784a3eac8c04
Fixes: a86a72a4a4e0 ("ocfs2: take ip_alloc_sem in ocfs2_dio_get_block & ocfs2_dio_end_io_write")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 17ba79f443ee..09146b43d1f0 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2294,8 +2294,6 @@ static int ocfs2_dio_end_io_write(struct inode *inode,
goto out;
}
- down_write(&oi->ip_alloc_sem);
-
/* Delete orphan before acquire i_rwsem. */
if (dwc->dw_orphaned) {
BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
@@ -2308,6 +2306,7 @@ static int ocfs2_dio_end_io_write(struct inode *inode,
mlog_errno(ret);
}
+ down_write(&oi->ip_alloc_sem);
di = (struct ocfs2_dinode *)di_bh->b_data;
ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
^ permalink raw reply related
* FAILED: patch "[PATCH] ocfs2: fix possible deadlock between unlink and" failed to apply to 5.10-stable tree
From: gregkh @ 2026-04-20 13:05 UTC (permalink / raw)
To: joseph.qi, akpm, gechangwei, heming.zhao, jiangqi903, jlbec,
junxiao.bi, mark, piaojun, stable
Cc: stable
The patch below does not apply to the 5.10-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@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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x b02da26a992db0c0e2559acbda0fc48d4a2fd337
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042003-rocking-engine-1cb6@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b02da26a992db0c0e2559acbda0fc48d4a2fd337 Mon Sep 17 00:00:00 2001
From: Joseph Qi <joseph.qi@linux.alibaba.com>
Date: Fri, 6 Mar 2026 11:22:11 +0800
Subject: [PATCH] ocfs2: fix possible deadlock between unlink and
dio_end_io_write
ocfs2_unlink takes orphan dir inode_lock first and then ip_alloc_sem,
while in ocfs2_dio_end_io_write, it acquires these locks in reverse order.
This creates an ABBA lock ordering violation on lock classes
ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] and
ocfs2_file_ip_alloc_sem_key.
Lock Chain #0 (orphan dir inode_lock -> ip_alloc_sem):
ocfs2_unlink
ocfs2_prepare_orphan_dir
ocfs2_lookup_lock_orphan_dir
inode_lock(orphan_dir_inode) <- lock A
__ocfs2_prepare_orphan_dir
ocfs2_prepare_dir_for_insert
ocfs2_extend_dir
ocfs2_expand_inline_dir
down_write(&oi->ip_alloc_sem) <- Lock B
Lock Chain #1 (ip_alloc_sem -> orphan dir inode_lock):
ocfs2_dio_end_io_write
down_write(&oi->ip_alloc_sem) <- Lock B
ocfs2_del_inode_from_orphan()
inode_lock(orphan_dir_inode) <- Lock A
Deadlock Scenario:
CPU0 (unlink) CPU1 (dio_end_io_write)
------ ------
inode_lock(orphan_dir_inode)
down_write(ip_alloc_sem)
down_write(ip_alloc_sem)
inode_lock(orphan_dir_inode)
Since ip_alloc_sem is to protect allocation changes, which is unrelated
with operations in ocfs2_del_inode_from_orphan. So move
ocfs2_del_inode_from_orphan out of ip_alloc_sem to fix the deadlock.
Link: https://lkml.kernel.org/r/20260306032211.1016452-1-joseph.qi@linux.alibaba.com
Reported-by: syzbot+67b90111784a3eac8c04@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=67b90111784a3eac8c04
Fixes: a86a72a4a4e0 ("ocfs2: take ip_alloc_sem in ocfs2_dio_get_block & ocfs2_dio_end_io_write")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 17ba79f443ee..09146b43d1f0 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2294,8 +2294,6 @@ static int ocfs2_dio_end_io_write(struct inode *inode,
goto out;
}
- down_write(&oi->ip_alloc_sem);
-
/* Delete orphan before acquire i_rwsem. */
if (dwc->dw_orphaned) {
BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
@@ -2308,6 +2306,7 @@ static int ocfs2_dio_end_io_write(struct inode *inode,
mlog_errno(ret);
}
+ down_write(&oi->ip_alloc_sem);
di = (struct ocfs2_dinode *)di_bh->b_data;
ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
^ permalink raw reply related
* FAILED: patch "[PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource" failed to apply to 6.12-stable tree
From: gregkh @ 2026-04-20 13:06 UTC (permalink / raw)
To: den, Frank.Li, mani; +Cc: stable
The patch below does not apply to the 6.12-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@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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 0da63230d3ec1ec5fcc443a2314233e95bfece54
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042022-dormitory-uncrushed-c526@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0da63230d3ec1ec5fcc443a2314233e95bfece54 Mon Sep 17 00:00:00 2001
From: Koichiro Den <den@valinux.co.jp>
Date: Thu, 26 Feb 2026 17:41:38 +0900
Subject: [PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource
teardown
epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to perform later. This leads to an oops when .allow_link fails
or when .drop_link is performed. The following is an example oops of the
former case:
Unable to handle kernel paging request at virtual address dead000000000108
[...]
[dead000000000108] address between user and kernel address ranges
Internal error: Oops: 0000000096000044 [#1] SMP
[...]
Call trace:
pci_epc_remove_epf+0x78/0xe0 (P)
pci_primary_epc_epf_link+0x88/0xa8
configfs_symlink+0x1f4/0x5a0
vfs_symlink+0x134/0x1d8
do_symlinkat+0x88/0x138
__arm64_sys_symlinkat+0x74/0xe0
[...]
Remove the helper, and drop pci_epc_put(). EPC device refcounting is
tied to the configfs EPC group lifetime, and pci_epc_put() in the
.drop_link path is sufficient.
Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260226084142.2226875-2-den@valinux.co.jp
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 148a3b160812..42c870ee3956 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -763,19 +763,6 @@ static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
}
}
-/**
- * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
- * @ntb: NTB device that facilitates communication between HOST and VHOST
- *
- * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
- */
-static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
-{
- pci_epc_remove_epf(ntb->epf->epc, ntb->epf, 0);
- pci_epc_put(ntb->epf->epc);
-}
-
-
/**
* epf_ntb_is_bar_used() - Check if a bar is used in the ntb configuration
* @ntb: NTB device that facilitates communication between HOST and VHOST
@@ -1529,7 +1516,7 @@ static int epf_ntb_bind(struct pci_epf *epf)
ret = epf_ntb_init_epc_bar(ntb);
if (ret) {
dev_err(dev, "Failed to create NTB EPC\n");
- goto err_bar_init;
+ return ret;
}
ret = epf_ntb_config_spad_bar_alloc(ntb);
@@ -1569,9 +1556,6 @@ static int epf_ntb_bind(struct pci_epf *epf)
err_bar_alloc:
epf_ntb_config_spad_bar_free(ntb);
-err_bar_init:
- epf_ntb_epc_destroy(ntb);
-
return ret;
}
@@ -1587,7 +1571,6 @@ static void epf_ntb_unbind(struct pci_epf *epf)
epf_ntb_epc_cleanup(ntb);
epf_ntb_config_spad_bar_free(ntb);
- epf_ntb_epc_destroy(ntb);
pci_unregister_driver(&vntb_pci_driver);
}
^ permalink raw reply related
* FAILED: patch "[PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource" failed to apply to 6.1-stable tree
From: gregkh @ 2026-04-20 13:06 UTC (permalink / raw)
To: den, Frank.Li, mani; +Cc: stable
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@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 0da63230d3ec1ec5fcc443a2314233e95bfece54
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042023-humiliate-slightly-3d92@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0da63230d3ec1ec5fcc443a2314233e95bfece54 Mon Sep 17 00:00:00 2001
From: Koichiro Den <den@valinux.co.jp>
Date: Thu, 26 Feb 2026 17:41:38 +0900
Subject: [PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource
teardown
epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to perform later. This leads to an oops when .allow_link fails
or when .drop_link is performed. The following is an example oops of the
former case:
Unable to handle kernel paging request at virtual address dead000000000108
[...]
[dead000000000108] address between user and kernel address ranges
Internal error: Oops: 0000000096000044 [#1] SMP
[...]
Call trace:
pci_epc_remove_epf+0x78/0xe0 (P)
pci_primary_epc_epf_link+0x88/0xa8
configfs_symlink+0x1f4/0x5a0
vfs_symlink+0x134/0x1d8
do_symlinkat+0x88/0x138
__arm64_sys_symlinkat+0x74/0xe0
[...]
Remove the helper, and drop pci_epc_put(). EPC device refcounting is
tied to the configfs EPC group lifetime, and pci_epc_put() in the
.drop_link path is sufficient.
Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260226084142.2226875-2-den@valinux.co.jp
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 148a3b160812..42c870ee3956 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -763,19 +763,6 @@ static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
}
}
-/**
- * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
- * @ntb: NTB device that facilitates communication between HOST and VHOST
- *
- * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
- */
-static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
-{
- pci_epc_remove_epf(ntb->epf->epc, ntb->epf, 0);
- pci_epc_put(ntb->epf->epc);
-}
-
-
/**
* epf_ntb_is_bar_used() - Check if a bar is used in the ntb configuration
* @ntb: NTB device that facilitates communication between HOST and VHOST
@@ -1529,7 +1516,7 @@ static int epf_ntb_bind(struct pci_epf *epf)
ret = epf_ntb_init_epc_bar(ntb);
if (ret) {
dev_err(dev, "Failed to create NTB EPC\n");
- goto err_bar_init;
+ return ret;
}
ret = epf_ntb_config_spad_bar_alloc(ntb);
@@ -1569,9 +1556,6 @@ static int epf_ntb_bind(struct pci_epf *epf)
err_bar_alloc:
epf_ntb_config_spad_bar_free(ntb);
-err_bar_init:
- epf_ntb_epc_destroy(ntb);
-
return ret;
}
@@ -1587,7 +1571,6 @@ static void epf_ntb_unbind(struct pci_epf *epf)
epf_ntb_epc_cleanup(ntb);
epf_ntb_config_spad_bar_free(ntb);
- epf_ntb_epc_destroy(ntb);
pci_unregister_driver(&vntb_pci_driver);
}
^ permalink raw reply related
* FAILED: patch "[PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource" failed to apply to 6.6-stable tree
From: gregkh @ 2026-04-20 13:06 UTC (permalink / raw)
To: den, Frank.Li, mani; +Cc: stable
The patch below does not apply to the 6.6-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@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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 0da63230d3ec1ec5fcc443a2314233e95bfece54
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042023-french-contents-6bee@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0da63230d3ec1ec5fcc443a2314233e95bfece54 Mon Sep 17 00:00:00 2001
From: Koichiro Den <den@valinux.co.jp>
Date: Thu, 26 Feb 2026 17:41:38 +0900
Subject: [PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource
teardown
epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to perform later. This leads to an oops when .allow_link fails
or when .drop_link is performed. The following is an example oops of the
former case:
Unable to handle kernel paging request at virtual address dead000000000108
[...]
[dead000000000108] address between user and kernel address ranges
Internal error: Oops: 0000000096000044 [#1] SMP
[...]
Call trace:
pci_epc_remove_epf+0x78/0xe0 (P)
pci_primary_epc_epf_link+0x88/0xa8
configfs_symlink+0x1f4/0x5a0
vfs_symlink+0x134/0x1d8
do_symlinkat+0x88/0x138
__arm64_sys_symlinkat+0x74/0xe0
[...]
Remove the helper, and drop pci_epc_put(). EPC device refcounting is
tied to the configfs EPC group lifetime, and pci_epc_put() in the
.drop_link path is sufficient.
Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260226084142.2226875-2-den@valinux.co.jp
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 148a3b160812..42c870ee3956 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -763,19 +763,6 @@ static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
}
}
-/**
- * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
- * @ntb: NTB device that facilitates communication between HOST and VHOST
- *
- * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
- */
-static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
-{
- pci_epc_remove_epf(ntb->epf->epc, ntb->epf, 0);
- pci_epc_put(ntb->epf->epc);
-}
-
-
/**
* epf_ntb_is_bar_used() - Check if a bar is used in the ntb configuration
* @ntb: NTB device that facilitates communication between HOST and VHOST
@@ -1529,7 +1516,7 @@ static int epf_ntb_bind(struct pci_epf *epf)
ret = epf_ntb_init_epc_bar(ntb);
if (ret) {
dev_err(dev, "Failed to create NTB EPC\n");
- goto err_bar_init;
+ return ret;
}
ret = epf_ntb_config_spad_bar_alloc(ntb);
@@ -1569,9 +1556,6 @@ static int epf_ntb_bind(struct pci_epf *epf)
err_bar_alloc:
epf_ntb_config_spad_bar_free(ntb);
-err_bar_init:
- epf_ntb_epc_destroy(ntb);
-
return ret;
}
@@ -1587,7 +1571,6 @@ static void epf_ntb_unbind(struct pci_epf *epf)
epf_ntb_epc_cleanup(ntb);
epf_ntb_config_spad_bar_free(ntb);
- epf_ntb_epc_destroy(ntb);
pci_unregister_driver(&vntb_pci_driver);
}
^ permalink raw reply related
* FAILED: patch "[PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource" failed to apply to 5.15-stable tree
From: gregkh @ 2026-04-20 13:06 UTC (permalink / raw)
To: den, Frank.Li, mani; +Cc: stable
The patch below does not apply to the 5.15-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@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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 0da63230d3ec1ec5fcc443a2314233e95bfece54
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042024-seldom-accuracy-953f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0da63230d3ec1ec5fcc443a2314233e95bfece54 Mon Sep 17 00:00:00 2001
From: Koichiro Den <den@valinux.co.jp>
Date: Thu, 26 Feb 2026 17:41:38 +0900
Subject: [PATCH] PCI: endpoint: pci-epf-vntb: Remove duplicate resource
teardown
epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to perform later. This leads to an oops when .allow_link fails
or when .drop_link is performed. The following is an example oops of the
former case:
Unable to handle kernel paging request at virtual address dead000000000108
[...]
[dead000000000108] address between user and kernel address ranges
Internal error: Oops: 0000000096000044 [#1] SMP
[...]
Call trace:
pci_epc_remove_epf+0x78/0xe0 (P)
pci_primary_epc_epf_link+0x88/0xa8
configfs_symlink+0x1f4/0x5a0
vfs_symlink+0x134/0x1d8
do_symlinkat+0x88/0x138
__arm64_sys_symlinkat+0x74/0xe0
[...]
Remove the helper, and drop pci_epc_put(). EPC device refcounting is
tied to the configfs EPC group lifetime, and pci_epc_put() in the
.drop_link path is sufficient.
Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260226084142.2226875-2-den@valinux.co.jp
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 148a3b160812..42c870ee3956 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -763,19 +763,6 @@ static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
}
}
-/**
- * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
- * @ntb: NTB device that facilitates communication between HOST and VHOST
- *
- * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
- */
-static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
-{
- pci_epc_remove_epf(ntb->epf->epc, ntb->epf, 0);
- pci_epc_put(ntb->epf->epc);
-}
-
-
/**
* epf_ntb_is_bar_used() - Check if a bar is used in the ntb configuration
* @ntb: NTB device that facilitates communication between HOST and VHOST
@@ -1529,7 +1516,7 @@ static int epf_ntb_bind(struct pci_epf *epf)
ret = epf_ntb_init_epc_bar(ntb);
if (ret) {
dev_err(dev, "Failed to create NTB EPC\n");
- goto err_bar_init;
+ return ret;
}
ret = epf_ntb_config_spad_bar_alloc(ntb);
@@ -1569,9 +1556,6 @@ static int epf_ntb_bind(struct pci_epf *epf)
err_bar_alloc:
epf_ntb_config_spad_bar_free(ntb);
-err_bar_init:
- epf_ntb_epc_destroy(ntb);
-
return ret;
}
@@ -1587,7 +1571,6 @@ static void epf_ntb_unbind(struct pci_epf *epf)
epf_ntb_epc_cleanup(ntb);
epf_ntb_config_spad_bar_free(ntb);
- epf_ntb_epc_destroy(ntb);
pci_unregister_driver(&vntb_pci_driver);
}
^ permalink raw reply related
* FAILED: patch "[PATCH] KVM: selftests: Remove duplicate LAUNCH_UPDATE_VMSA call in" failed to apply to 6.12-stable tree
From: gregkh @ 2026-04-20 13:07 UTC (permalink / raw)
To: seanjc; +Cc: stable
The patch below does not apply to the 6.12-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@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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 25a642b6abc98bbbabbf2baef9fc498bbea6aee6
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042008-thesis-flatworm-d8ed@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 25a642b6abc98bbbabbf2baef9fc498bbea6aee6 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 10 Mar 2026 16:48:09 -0700
Subject: [PATCH] KVM: selftests: Remove duplicate LAUNCH_UPDATE_VMSA call in
SEV-ES migrate test
Drop the explicit KVM_SEV_LAUNCH_UPDATE_VMSA call when creating an SEV-ES
VM in the SEV migration test, as sev_vm_create() automatically updates the
VMSA pages for SEV-ES guests. The only reason the duplicate call doesn't
cause visible problems is because the test doesn't actually try to run the
vCPUs. That will change when KVM adds a check to prevent userspace from
re-launching a VMSA (which corrupts the VMSA page due to KVM writing
encrypted private memory).
Fixes: 69f8e15ab61f ("KVM: selftests: Use the SEV library APIs in the intra-host migration test")
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260310234829.2608037-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c b/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
index 0a6dfba3905b..6b0928e69051 100644
--- a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
+++ b/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
@@ -36,8 +36,6 @@ static struct kvm_vm *sev_vm_create(bool es)
sev_vm_launch(vm, es ? SEV_POLICY_ES : 0);
- if (es)
- vm_sev_ioctl(vm, KVM_SEV_LAUNCH_UPDATE_VMSA, NULL);
return vm;
}
^ permalink raw reply related
* FAILED: patch "[PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with" failed to apply to 6.12-stable tree
From: gregkh @ 2026-04-20 13:07 UTC (permalink / raw)
To: seanjc, glider; +Cc: stable
The patch below does not apply to the 6.12-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@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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x b6408b6cec5df76a165575777800ef2aba12b109
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042035-mothproof-waged-0e72@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b6408b6cec5df76a165575777800ef2aba12b109 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 10 Mar 2026 16:48:11 -0700
Subject: [PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with
kvm->lock
Take and hold kvm->lock for before checking sev_guest() in
sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock
is held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't
rollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to
a not-yet-initialized sev->regions_list, e.g. triggering a #GP
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83
Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00
RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000
RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000
R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000
R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000
FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0
Call Trace:
<TASK>
kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371
kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363
__se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f34e9f7e9a9
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9
RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007
RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8
</TASK>
with a syzlang reproducer that looks like:
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB="..."], 0x4f}) (async)
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)
r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)
ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)
ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async)
ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async)
r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)
openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async)
ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async)
r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2)
close(r0) (async)
openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async)
ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async)
ioctl$KVM_RUN(r5, 0xae80, 0x0)
Opportunistically use guard() to avoid having to define a new error label
and goto usage.
Fixes: 1e80fdc09d12 ("KVM: SVM: Pin guest memory when SEV is active")
Cc: stable@vger.kernel.org
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://patch.msgid.link/20260310234829.2608037-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d29783c3075a..9265ebd9aa18 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2706,6 +2706,8 @@ int sev_mem_enc_register_region(struct kvm *kvm,
struct enc_region *region;
int ret = 0;
+ guard(mutex)(&kvm->lock);
+
if (!sev_guest(kvm))
return -ENOTTY;
@@ -2717,12 +2719,10 @@ int sev_mem_enc_register_region(struct kvm *kvm,
if (!region)
return -ENOMEM;
- mutex_lock(&kvm->lock);
region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages,
FOLL_WRITE | FOLL_LONGTERM);
if (IS_ERR(region->pages)) {
ret = PTR_ERR(region->pages);
- mutex_unlock(&kvm->lock);
goto e_free;
}
@@ -2740,8 +2740,6 @@ int sev_mem_enc_register_region(struct kvm *kvm,
region->size = range->size;
list_add_tail(®ion->list, &sev->regions_list);
- mutex_unlock(&kvm->lock);
-
return ret;
e_free:
^ permalink raw reply related
* FAILED: patch "[PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with" failed to apply to 6.6-stable tree
From: gregkh @ 2026-04-20 13:07 UTC (permalink / raw)
To: seanjc, glider; +Cc: stable
The patch below does not apply to the 6.6-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@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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x b6408b6cec5df76a165575777800ef2aba12b109
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042036-collide-cofounder-f1d3@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b6408b6cec5df76a165575777800ef2aba12b109 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 10 Mar 2026 16:48:11 -0700
Subject: [PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with
kvm->lock
Take and hold kvm->lock for before checking sev_guest() in
sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock
is held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't
rollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to
a not-yet-initialized sev->regions_list, e.g. triggering a #GP
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83
Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00
RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000
RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000
R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000
R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000
FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0
Call Trace:
<TASK>
kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371
kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363
__se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f34e9f7e9a9
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9
RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007
RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8
</TASK>
with a syzlang reproducer that looks like:
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB="..."], 0x4f}) (async)
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)
r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)
ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)
ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async)
ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async)
r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)
openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async)
ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async)
r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2)
close(r0) (async)
openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async)
ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async)
ioctl$KVM_RUN(r5, 0xae80, 0x0)
Opportunistically use guard() to avoid having to define a new error label
and goto usage.
Fixes: 1e80fdc09d12 ("KVM: SVM: Pin guest memory when SEV is active")
Cc: stable@vger.kernel.org
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://patch.msgid.link/20260310234829.2608037-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d29783c3075a..9265ebd9aa18 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2706,6 +2706,8 @@ int sev_mem_enc_register_region(struct kvm *kvm,
struct enc_region *region;
int ret = 0;
+ guard(mutex)(&kvm->lock);
+
if (!sev_guest(kvm))
return -ENOTTY;
@@ -2717,12 +2719,10 @@ int sev_mem_enc_register_region(struct kvm *kvm,
if (!region)
return -ENOMEM;
- mutex_lock(&kvm->lock);
region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages,
FOLL_WRITE | FOLL_LONGTERM);
if (IS_ERR(region->pages)) {
ret = PTR_ERR(region->pages);
- mutex_unlock(&kvm->lock);
goto e_free;
}
@@ -2740,8 +2740,6 @@ int sev_mem_enc_register_region(struct kvm *kvm,
region->size = range->size;
list_add_tail(®ion->list, &sev->regions_list);
- mutex_unlock(&kvm->lock);
-
return ret;
e_free:
^ permalink raw reply related
* FAILED: patch "[PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with" failed to apply to 6.1-stable tree
From: gregkh @ 2026-04-20 13:07 UTC (permalink / raw)
To: seanjc, glider; +Cc: stable
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@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 b6408b6cec5df76a165575777800ef2aba12b109
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042038-cable-curly-8e1b@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b6408b6cec5df76a165575777800ef2aba12b109 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 10 Mar 2026 16:48:11 -0700
Subject: [PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with
kvm->lock
Take and hold kvm->lock for before checking sev_guest() in
sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock
is held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't
rollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to
a not-yet-initialized sev->regions_list, e.g. triggering a #GP
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83
Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00
RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000
RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000
R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000
R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000
FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0
Call Trace:
<TASK>
kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371
kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363
__se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f34e9f7e9a9
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9
RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007
RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8
</TASK>
with a syzlang reproducer that looks like:
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB="..."], 0x4f}) (async)
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)
r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)
ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)
ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async)
ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async)
r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)
openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async)
ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async)
r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2)
close(r0) (async)
openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async)
ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async)
ioctl$KVM_RUN(r5, 0xae80, 0x0)
Opportunistically use guard() to avoid having to define a new error label
and goto usage.
Fixes: 1e80fdc09d12 ("KVM: SVM: Pin guest memory when SEV is active")
Cc: stable@vger.kernel.org
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://patch.msgid.link/20260310234829.2608037-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d29783c3075a..9265ebd9aa18 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2706,6 +2706,8 @@ int sev_mem_enc_register_region(struct kvm *kvm,
struct enc_region *region;
int ret = 0;
+ guard(mutex)(&kvm->lock);
+
if (!sev_guest(kvm))
return -ENOTTY;
@@ -2717,12 +2719,10 @@ int sev_mem_enc_register_region(struct kvm *kvm,
if (!region)
return -ENOMEM;
- mutex_lock(&kvm->lock);
region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages,
FOLL_WRITE | FOLL_LONGTERM);
if (IS_ERR(region->pages)) {
ret = PTR_ERR(region->pages);
- mutex_unlock(&kvm->lock);
goto e_free;
}
@@ -2740,8 +2740,6 @@ int sev_mem_enc_register_region(struct kvm *kvm,
region->size = range->size;
list_add_tail(®ion->list, &sev->regions_list);
- mutex_unlock(&kvm->lock);
-
return ret;
e_free:
^ permalink raw reply related
* FAILED: patch "[PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with" failed to apply to 5.15-stable tree
From: gregkh @ 2026-04-20 13:07 UTC (permalink / raw)
To: seanjc, glider; +Cc: stable
The patch below does not apply to the 5.15-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@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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x b6408b6cec5df76a165575777800ef2aba12b109
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042039-debrief-blabber-3a74@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b6408b6cec5df76a165575777800ef2aba12b109 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 10 Mar 2026 16:48:11 -0700
Subject: [PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with
kvm->lock
Take and hold kvm->lock for before checking sev_guest() in
sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock
is held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't
rollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to
a not-yet-initialized sev->regions_list, e.g. triggering a #GP
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83
Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00
RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000
RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000
R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000
R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000
FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0
Call Trace:
<TASK>
kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371
kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363
__se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f34e9f7e9a9
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9
RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007
RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8
</TASK>
with a syzlang reproducer that looks like:
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB="..."], 0x4f}) (async)
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)
r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)
ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)
ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async)
ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async)
r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)
openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async)
ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async)
r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2)
close(r0) (async)
openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async)
ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async)
ioctl$KVM_RUN(r5, 0xae80, 0x0)
Opportunistically use guard() to avoid having to define a new error label
and goto usage.
Fixes: 1e80fdc09d12 ("KVM: SVM: Pin guest memory when SEV is active")
Cc: stable@vger.kernel.org
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://patch.msgid.link/20260310234829.2608037-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d29783c3075a..9265ebd9aa18 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2706,6 +2706,8 @@ int sev_mem_enc_register_region(struct kvm *kvm,
struct enc_region *region;
int ret = 0;
+ guard(mutex)(&kvm->lock);
+
if (!sev_guest(kvm))
return -ENOTTY;
@@ -2717,12 +2719,10 @@ int sev_mem_enc_register_region(struct kvm *kvm,
if (!region)
return -ENOMEM;
- mutex_lock(&kvm->lock);
region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages,
FOLL_WRITE | FOLL_LONGTERM);
if (IS_ERR(region->pages)) {
ret = PTR_ERR(region->pages);
- mutex_unlock(&kvm->lock);
goto e_free;
}
@@ -2740,8 +2740,6 @@ int sev_mem_enc_register_region(struct kvm *kvm,
region->size = range->size;
list_add_tail(®ion->list, &sev->regions_list);
- mutex_unlock(&kvm->lock);
-
return ret;
e_free:
^ permalink raw reply related
* FAILED: patch "[PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with" failed to apply to 5.10-stable tree
From: gregkh @ 2026-04-20 13:07 UTC (permalink / raw)
To: seanjc, glider; +Cc: stable
The patch below does not apply to the 5.10-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@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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x b6408b6cec5df76a165575777800ef2aba12b109
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042040-strum-curse-8dcd@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b6408b6cec5df76a165575777800ef2aba12b109 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 10 Mar 2026 16:48:11 -0700
Subject: [PATCH] KVM: SEV: Protect *all* of sev_mem_enc_register_region() with
kvm->lock
Take and hold kvm->lock for before checking sev_guest() in
sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock
is held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't
rollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to
a not-yet-initialized sev->regions_list, e.g. triggering a #GP
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83
Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00
RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000
RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000
R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000
R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000
FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0
Call Trace:
<TASK>
kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371
kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363
__se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f34e9f7e9a9
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9
RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007
RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8
</TASK>
with a syzlang reproducer that looks like:
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB="..."], 0x4f}) (async)
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)
r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)
ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)
ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async)
ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async)
r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)
openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async)
ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async)
r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2)
close(r0) (async)
openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async)
ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async)
ioctl$KVM_RUN(r5, 0xae80, 0x0)
Opportunistically use guard() to avoid having to define a new error label
and goto usage.
Fixes: 1e80fdc09d12 ("KVM: SVM: Pin guest memory when SEV is active")
Cc: stable@vger.kernel.org
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://patch.msgid.link/20260310234829.2608037-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d29783c3075a..9265ebd9aa18 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2706,6 +2706,8 @@ int sev_mem_enc_register_region(struct kvm *kvm,
struct enc_region *region;
int ret = 0;
+ guard(mutex)(&kvm->lock);
+
if (!sev_guest(kvm))
return -ENOTTY;
@@ -2717,12 +2719,10 @@ int sev_mem_enc_register_region(struct kvm *kvm,
if (!region)
return -ENOMEM;
- mutex_lock(&kvm->lock);
region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages,
FOLL_WRITE | FOLL_LONGTERM);
if (IS_ERR(region->pages)) {
ret = PTR_ERR(region->pages);
- mutex_unlock(&kvm->lock);
goto e_free;
}
@@ -2740,8 +2740,6 @@ int sev_mem_enc_register_region(struct kvm *kvm,
region->size = range->size;
list_add_tail(®ion->list, &sev->regions_list);
- mutex_unlock(&kvm->lock);
-
return ret;
e_free:
^ permalink raw reply related
* FAILED: patch "[PATCH] mm/pagewalk: fix race between concurrent split and refault" failed to apply to 7.0-stable tree
From: gregkh @ 2026-04-20 13:08 UTC (permalink / raw)
To: mboone, akpm, david, liam.howlett, ljs, mhocko, rppt, stable,
surenb, vbabka
Cc: stable
The patch below does not apply to the 7.0-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@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-7.0.y
git checkout FETCH_HEAD
git cherry-pick -x 9b25a6e3d243a8ce14eeaf74082c621a9944c776
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042031-unmoved-approach-a81c@gregkh' --subject-prefix 'PATCH 7.0.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9b25a6e3d243a8ce14eeaf74082c621a9944c776 Mon Sep 17 00:00:00 2001
From: Max Boone <mboone@akamai.com>
Date: Wed, 25 Mar 2026 10:59:16 +0100
Subject: [PATCH] mm/pagewalk: fix race between concurrent split and refault
The splitting of a PUD entry in walk_pud_range() can race with a
concurrent thread refaulting the PUD leaf entry causing it to try walking
a PMD range that has disappeared.
An example and reproduction of this is to try reading numa_maps of a
process while VFIO-PCI is setting up DMA (specifically the
vfio_pin_pages_remote call) on a large BAR for that process.
This will trigger a kernel BUG:
vfio-pci 0000:03:00.0: enabling device (0000 -> 0002)
BUG: unable to handle page fault for address: ffffa23980000000
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
...
RIP: 0010:walk_pgd_range+0x3b5/0x7a0
Code: 8d 43 ff 48 89 44 24 28 4d 89 ce 4d 8d a7 00 00 20 00 48 8b 4c 24
28 49 81 e4 00 00 e0 ff 49 8d 44 24 ff 48 39 c8 4c 0f 43 e3 <49> f7 06
9f ff ff ff 75 3b 48 8b 44 24 20 48 8b 40 28 48 85 c0 74
RSP: 0018:ffffac23e1ecf808 EFLAGS: 00010287
RAX: 00007f44c01fffff RBX: 00007f4500000000 RCX: 00007f44ffffffff
RDX: 0000000000000000 RSI: 000ffffffffff000 RDI: ffffffff93378fe0
RBP: ffffac23e1ecf918 R08: 0000000000000004 R09: ffffa23980000000
R10: 0000000000000020 R11: 0000000000000004 R12: 00007f44c0200000
R13: 00007f44c0000000 R14: ffffa23980000000 R15: 00007f44c0000000
FS: 00007fe884739580(0000) GS:ffff9b7d7a9c0000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffa23980000000 CR3: 000000c0650e2005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<TASK>
__walk_page_range+0x195/0x1b0
walk_page_vma+0x62/0xc0
show_numa_map+0x12b/0x3b0
seq_read_iter+0x297/0x440
seq_read+0x11d/0x140
vfs_read+0xc2/0x340
ksys_read+0x5f/0xe0
do_syscall_64+0x68/0x130
? get_page_from_freelist+0x5c2/0x17e0
? mas_store_prealloc+0x17e/0x360
? vma_set_page_prot+0x4c/0xa0
? __alloc_pages_noprof+0x14e/0x2d0
? __mod_memcg_lruvec_state+0x8d/0x140
? __lruvec_stat_mod_folio+0x76/0xb0
? __folio_mod_stat+0x26/0x80
? do_anonymous_page+0x705/0x900
? __handle_mm_fault+0xa8d/0x1000
? __count_memcg_events+0x53/0xf0
? handle_mm_fault+0xa5/0x360
? do_user_addr_fault+0x342/0x640
? arch_exit_to_user_mode_prepare.constprop.0+0x16/0xa0
? irqentry_exit_to_user_mode+0x24/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fe88464f47e
Code: c0 e9 b6 fe ff ff 50 48 8d 3d be 07 0b 00 e8 69 01 02 00 66 0f 1f
84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00
f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28
RSP: 002b:00007ffe6cd9a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fe88464f47e
RDX: 0000000000020000 RSI: 00007fe884543000 RDI: 0000000000000003
RBP: 00007fe884543000 R08: 00007fe884542010 R09: 0000000000000000
R10: fffffffffffffbc5 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
</TASK>
Fix this by validating the PUD entry in walk_pmd_range() using a stable
snapshot (pudp_get()). If the PUD is not present or is a leaf, retry the
walk via ACTION_AGAIN instead of descending further. This mirrors the
retry logic in walk_pte_range(), which lets walk_pmd_range() retry if the
PTE is not being got by pte_offset_map_lock().
Link: https://lkml.kernel.org/r/20260325-pagewalk-check-pmd-refault-v2-1-707bff33bc60@akamai.com
Fixes: f9e54c3a2f5b ("vfio/pci: implement huge_fault support")
Co-developed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Max Boone <mboone@akamai.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index cb358558807c..3ae2586ff45b 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -96,6 +96,7 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
+ pud_t pudval = pudp_get(pud);
pmd_t *pmd;
unsigned long next;
const struct mm_walk_ops *ops = walk->ops;
@@ -104,6 +105,24 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
int err = 0;
int depth = real_depth(3);
+ /*
+ * For PTE handling, pte_offset_map_lock() takes care of checking
+ * whether there actually is a page table. But it also has to be
+ * very careful about concurrent page table reclaim.
+ *
+ * Similarly, we have to be careful here - a PUD entry that points
+ * to a PMD table cannot go away, so we can just walk it. But if
+ * it's something else, we need to ensure we didn't race something,
+ * so need to retry.
+ *
+ * A pertinent example of this is a PUD refault after PUD split -
+ * we will need to split again or risk accessing invalid memory.
+ */
+ if (!pud_present(pudval) || pud_leaf(pudval)) {
+ walk->action = ACTION_AGAIN;
+ return 0;
+ }
+
pmd = pmd_offset(pud, addr);
do {
again:
@@ -217,12 +236,12 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
else if (pud_leaf(*pud) || !pud_present(*pud))
continue; /* Nothing to do. */
- if (pud_none(*pud))
- goto again;
-
err = walk_pmd_range(pud, addr, next, walk);
if (err)
break;
+
+ if (walk->action == ACTION_AGAIN)
+ goto again;
} while (pud++, addr = next, addr != end);
return err;
^ permalink raw reply related
* FAILED: patch "[PATCH] mm/pagewalk: fix race between concurrent split and refault" failed to apply to 6.19-stable tree
From: gregkh @ 2026-04-20 13:08 UTC (permalink / raw)
To: mboone, akpm, david, liam.howlett, ljs, mhocko, rppt, stable,
surenb, vbabka
Cc: stable
The patch below does not apply to the 6.19-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@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-6.19.y
git checkout FETCH_HEAD
git cherry-pick -x 9b25a6e3d243a8ce14eeaf74082c621a9944c776
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042033-emote-enactment-a70e@gregkh' --subject-prefix 'PATCH 6.19.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9b25a6e3d243a8ce14eeaf74082c621a9944c776 Mon Sep 17 00:00:00 2001
From: Max Boone <mboone@akamai.com>
Date: Wed, 25 Mar 2026 10:59:16 +0100
Subject: [PATCH] mm/pagewalk: fix race between concurrent split and refault
The splitting of a PUD entry in walk_pud_range() can race with a
concurrent thread refaulting the PUD leaf entry causing it to try walking
a PMD range that has disappeared.
An example and reproduction of this is to try reading numa_maps of a
process while VFIO-PCI is setting up DMA (specifically the
vfio_pin_pages_remote call) on a large BAR for that process.
This will trigger a kernel BUG:
vfio-pci 0000:03:00.0: enabling device (0000 -> 0002)
BUG: unable to handle page fault for address: ffffa23980000000
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
...
RIP: 0010:walk_pgd_range+0x3b5/0x7a0
Code: 8d 43 ff 48 89 44 24 28 4d 89 ce 4d 8d a7 00 00 20 00 48 8b 4c 24
28 49 81 e4 00 00 e0 ff 49 8d 44 24 ff 48 39 c8 4c 0f 43 e3 <49> f7 06
9f ff ff ff 75 3b 48 8b 44 24 20 48 8b 40 28 48 85 c0 74
RSP: 0018:ffffac23e1ecf808 EFLAGS: 00010287
RAX: 00007f44c01fffff RBX: 00007f4500000000 RCX: 00007f44ffffffff
RDX: 0000000000000000 RSI: 000ffffffffff000 RDI: ffffffff93378fe0
RBP: ffffac23e1ecf918 R08: 0000000000000004 R09: ffffa23980000000
R10: 0000000000000020 R11: 0000000000000004 R12: 00007f44c0200000
R13: 00007f44c0000000 R14: ffffa23980000000 R15: 00007f44c0000000
FS: 00007fe884739580(0000) GS:ffff9b7d7a9c0000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffa23980000000 CR3: 000000c0650e2005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<TASK>
__walk_page_range+0x195/0x1b0
walk_page_vma+0x62/0xc0
show_numa_map+0x12b/0x3b0
seq_read_iter+0x297/0x440
seq_read+0x11d/0x140
vfs_read+0xc2/0x340
ksys_read+0x5f/0xe0
do_syscall_64+0x68/0x130
? get_page_from_freelist+0x5c2/0x17e0
? mas_store_prealloc+0x17e/0x360
? vma_set_page_prot+0x4c/0xa0
? __alloc_pages_noprof+0x14e/0x2d0
? __mod_memcg_lruvec_state+0x8d/0x140
? __lruvec_stat_mod_folio+0x76/0xb0
? __folio_mod_stat+0x26/0x80
? do_anonymous_page+0x705/0x900
? __handle_mm_fault+0xa8d/0x1000
? __count_memcg_events+0x53/0xf0
? handle_mm_fault+0xa5/0x360
? do_user_addr_fault+0x342/0x640
? arch_exit_to_user_mode_prepare.constprop.0+0x16/0xa0
? irqentry_exit_to_user_mode+0x24/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fe88464f47e
Code: c0 e9 b6 fe ff ff 50 48 8d 3d be 07 0b 00 e8 69 01 02 00 66 0f 1f
84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00
f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28
RSP: 002b:00007ffe6cd9a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fe88464f47e
RDX: 0000000000020000 RSI: 00007fe884543000 RDI: 0000000000000003
RBP: 00007fe884543000 R08: 00007fe884542010 R09: 0000000000000000
R10: fffffffffffffbc5 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
</TASK>
Fix this by validating the PUD entry in walk_pmd_range() using a stable
snapshot (pudp_get()). If the PUD is not present or is a leaf, retry the
walk via ACTION_AGAIN instead of descending further. This mirrors the
retry logic in walk_pte_range(), which lets walk_pmd_range() retry if the
PTE is not being got by pte_offset_map_lock().
Link: https://lkml.kernel.org/r/20260325-pagewalk-check-pmd-refault-v2-1-707bff33bc60@akamai.com
Fixes: f9e54c3a2f5b ("vfio/pci: implement huge_fault support")
Co-developed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Max Boone <mboone@akamai.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index cb358558807c..3ae2586ff45b 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -96,6 +96,7 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
+ pud_t pudval = pudp_get(pud);
pmd_t *pmd;
unsigned long next;
const struct mm_walk_ops *ops = walk->ops;
@@ -104,6 +105,24 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
int err = 0;
int depth = real_depth(3);
+ /*
+ * For PTE handling, pte_offset_map_lock() takes care of checking
+ * whether there actually is a page table. But it also has to be
+ * very careful about concurrent page table reclaim.
+ *
+ * Similarly, we have to be careful here - a PUD entry that points
+ * to a PMD table cannot go away, so we can just walk it. But if
+ * it's something else, we need to ensure we didn't race something,
+ * so need to retry.
+ *
+ * A pertinent example of this is a PUD refault after PUD split -
+ * we will need to split again or risk accessing invalid memory.
+ */
+ if (!pud_present(pudval) || pud_leaf(pudval)) {
+ walk->action = ACTION_AGAIN;
+ return 0;
+ }
+
pmd = pmd_offset(pud, addr);
do {
again:
@@ -217,12 +236,12 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
else if (pud_leaf(*pud) || !pud_present(*pud))
continue; /* Nothing to do. */
- if (pud_none(*pud))
- goto again;
-
err = walk_pmd_range(pud, addr, next, walk);
if (err)
break;
+
+ if (walk->action == ACTION_AGAIN)
+ goto again;
} while (pud++, addr = next, addr != end);
return err;
^ permalink raw reply related
* FAILED: patch "[PATCH] mm/pagewalk: fix race between concurrent split and refault" failed to apply to 6.18-stable tree
From: gregkh @ 2026-04-20 13:08 UTC (permalink / raw)
To: mboone, akpm, david, liam.howlett, ljs, mhocko, rppt, stable,
surenb, vbabka
Cc: stable
The patch below does not apply to the 6.18-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@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-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 9b25a6e3d243a8ce14eeaf74082c621a9944c776
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026042034-sake-nape-a60e@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9b25a6e3d243a8ce14eeaf74082c621a9944c776 Mon Sep 17 00:00:00 2001
From: Max Boone <mboone@akamai.com>
Date: Wed, 25 Mar 2026 10:59:16 +0100
Subject: [PATCH] mm/pagewalk: fix race between concurrent split and refault
The splitting of a PUD entry in walk_pud_range() can race with a
concurrent thread refaulting the PUD leaf entry causing it to try walking
a PMD range that has disappeared.
An example and reproduction of this is to try reading numa_maps of a
process while VFIO-PCI is setting up DMA (specifically the
vfio_pin_pages_remote call) on a large BAR for that process.
This will trigger a kernel BUG:
vfio-pci 0000:03:00.0: enabling device (0000 -> 0002)
BUG: unable to handle page fault for address: ffffa23980000000
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
...
RIP: 0010:walk_pgd_range+0x3b5/0x7a0
Code: 8d 43 ff 48 89 44 24 28 4d 89 ce 4d 8d a7 00 00 20 00 48 8b 4c 24
28 49 81 e4 00 00 e0 ff 49 8d 44 24 ff 48 39 c8 4c 0f 43 e3 <49> f7 06
9f ff ff ff 75 3b 48 8b 44 24 20 48 8b 40 28 48 85 c0 74
RSP: 0018:ffffac23e1ecf808 EFLAGS: 00010287
RAX: 00007f44c01fffff RBX: 00007f4500000000 RCX: 00007f44ffffffff
RDX: 0000000000000000 RSI: 000ffffffffff000 RDI: ffffffff93378fe0
RBP: ffffac23e1ecf918 R08: 0000000000000004 R09: ffffa23980000000
R10: 0000000000000020 R11: 0000000000000004 R12: 00007f44c0200000
R13: 00007f44c0000000 R14: ffffa23980000000 R15: 00007f44c0000000
FS: 00007fe884739580(0000) GS:ffff9b7d7a9c0000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffa23980000000 CR3: 000000c0650e2005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<TASK>
__walk_page_range+0x195/0x1b0
walk_page_vma+0x62/0xc0
show_numa_map+0x12b/0x3b0
seq_read_iter+0x297/0x440
seq_read+0x11d/0x140
vfs_read+0xc2/0x340
ksys_read+0x5f/0xe0
do_syscall_64+0x68/0x130
? get_page_from_freelist+0x5c2/0x17e0
? mas_store_prealloc+0x17e/0x360
? vma_set_page_prot+0x4c/0xa0
? __alloc_pages_noprof+0x14e/0x2d0
? __mod_memcg_lruvec_state+0x8d/0x140
? __lruvec_stat_mod_folio+0x76/0xb0
? __folio_mod_stat+0x26/0x80
? do_anonymous_page+0x705/0x900
? __handle_mm_fault+0xa8d/0x1000
? __count_memcg_events+0x53/0xf0
? handle_mm_fault+0xa5/0x360
? do_user_addr_fault+0x342/0x640
? arch_exit_to_user_mode_prepare.constprop.0+0x16/0xa0
? irqentry_exit_to_user_mode+0x24/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fe88464f47e
Code: c0 e9 b6 fe ff ff 50 48 8d 3d be 07 0b 00 e8 69 01 02 00 66 0f 1f
84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00
f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28
RSP: 002b:00007ffe6cd9a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fe88464f47e
RDX: 0000000000020000 RSI: 00007fe884543000 RDI: 0000000000000003
RBP: 00007fe884543000 R08: 00007fe884542010 R09: 0000000000000000
R10: fffffffffffffbc5 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
</TASK>
Fix this by validating the PUD entry in walk_pmd_range() using a stable
snapshot (pudp_get()). If the PUD is not present or is a leaf, retry the
walk via ACTION_AGAIN instead of descending further. This mirrors the
retry logic in walk_pte_range(), which lets walk_pmd_range() retry if the
PTE is not being got by pte_offset_map_lock().
Link: https://lkml.kernel.org/r/20260325-pagewalk-check-pmd-refault-v2-1-707bff33bc60@akamai.com
Fixes: f9e54c3a2f5b ("vfio/pci: implement huge_fault support")
Co-developed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Max Boone <mboone@akamai.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index cb358558807c..3ae2586ff45b 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -96,6 +96,7 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
+ pud_t pudval = pudp_get(pud);
pmd_t *pmd;
unsigned long next;
const struct mm_walk_ops *ops = walk->ops;
@@ -104,6 +105,24 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
int err = 0;
int depth = real_depth(3);
+ /*
+ * For PTE handling, pte_offset_map_lock() takes care of checking
+ * whether there actually is a page table. But it also has to be
+ * very careful about concurrent page table reclaim.
+ *
+ * Similarly, we have to be careful here - a PUD entry that points
+ * to a PMD table cannot go away, so we can just walk it. But if
+ * it's something else, we need to ensure we didn't race something,
+ * so need to retry.
+ *
+ * A pertinent example of this is a PUD refault after PUD split -
+ * we will need to split again or risk accessing invalid memory.
+ */
+ if (!pud_present(pudval) || pud_leaf(pudval)) {
+ walk->action = ACTION_AGAIN;
+ return 0;
+ }
+
pmd = pmd_offset(pud, addr);
do {
again:
@@ -217,12 +236,12 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
else if (pud_leaf(*pud) || !pud_present(*pud))
continue; /* Nothing to do. */
- if (pud_none(*pud))
- goto again;
-
err = walk_pmd_range(pud, addr, next, walk);
if (err)
break;
+
+ if (walk->action == ACTION_AGAIN)
+ goto again;
} while (pud++, addr = next, addr != end);
return err;
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