The patch below does not apply to the 6.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.16.y
git checkout FETCH_HEAD
git cherry-pick -x c62cff40481c037307a13becbda795f7afdcfebd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092116-ceramics-stratus-5d18@gregkh' --subject-prefix 'PATCH 6.16.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c62cff40481c037307a13becbda795f7afdcfebd Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Mon, 8 Sep 2025 19:22:38 -0700
Subject: [PATCH] samples/damon/mtier: avoid starting DAMON before
initialization
Commit 964314344eab ("samples/damon/mtier: support boot time enable
setup") is somehow incompletely applying the origin patch [1]. It is
missing the part that avoids starting DAMON before module initialization.
Probably a mistake during a merge has happened. Fix it by applying the
missed part again.
Link: https://lkml.kernel.org/r/20250909022238.2989-4-sj@kernel.org
Link: https://lore.kernel.org/20250706193207.39810-4-sj@kernel.org [1]
Fixes: 964314344eab ("samples/damon/mtier: support boot time enable setup")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/samples/damon/mtier.c b/samples/damon/mtier.c
index 7ebd352138e4..beaf36657dea 100644
--- a/samples/damon/mtier.c
+++ b/samples/damon/mtier.c
@@ -208,6 +208,9 @@ static int damon_sample_mtier_enable_store(
if (enabled == is_enabled)
return 0;
+ if (!init_called)
+ return 0;
+
if (enabled) {
err = damon_sample_mtier_start();
if (err)
The patch below does not apply to the 6.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.16.y
git checkout FETCH_HEAD
git cherry-pick -x f826edeb888c5a8bd1b6e95ae6a50b0db2b21902
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092111-specked-enviably-906d@gregkh' --subject-prefix 'PATCH 6.16.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f826edeb888c5a8bd1b6e95ae6a50b0db2b21902 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Mon, 8 Sep 2025 19:22:36 -0700
Subject: [PATCH] samples/damon/wsse: avoid starting DAMON before
initialization
Patch series "samples/damon: fix boot time enable handling fixup merge
mistakes".
First three patches of the patch series "mm/damon: fix misc bugs in DAMON
modules" [1] were trying to fix boot time DAMON sample modules enabling
issues. The issues are the modules can crash if those are enabled before
DAMON is enabled, like using boot time parameter options. The three
patches were fixing the issues by avoiding starting DAMON before the
module initialization phase.
However, probably by a mistake during a merge, only half of the change is
merged, and the part for avoiding the starting of DAMON before the module
initialized is missed. So the problem is not solved and thus the modules
can still crash if enabled before DAMON is initialized. Fix those by
applying the unmerged parts again.
Note that the broken commits are merged into 6.17-rc1, but also backported
to relevant stable kernels. So this series also needs to be merged into
the stable kernels. Hence Cc-ing stable@.
This patch (of 3):
Commit 0ed1165c3727 ("samples/damon/wsse: fix boot time enable handling")
is somehow incompletely applying the origin patch [2]. It is missing the
part that avoids starting DAMON before module initialization. Probably a
mistake during a merge has happened. Fix it by applying the missed part
again.
Link: https://lkml.kernel.org/r/20250909022238.2989-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250909022238.2989-2-sj@kernel.org
Link: https://lkml.kernel.org/r/20250706193207.39810-1-sj@kernel.org [1]
Link: https://lore.kernel.org/20250706193207.39810-2-sj@kernel.org [2]
Fixes: 0ed1165c3727 ("samples/damon/wsse: fix boot time enable handling")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/samples/damon/wsse.c b/samples/damon/wsse.c
index da052023b099..21eaf15f987d 100644
--- a/samples/damon/wsse.c
+++ b/samples/damon/wsse.c
@@ -118,6 +118,9 @@ static int damon_sample_wsse_enable_store(
return 0;
if (enabled) {
+ if (!init_called)
+ return 0;
+
err = damon_sample_wsse_start();
if (err)
enabled = false;
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 3539b1467e94336d5854ebf976d9627bfb65d6c3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092128-embassy-flyable-e3fb@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3539b1467e94336d5854ebf976d9627bfb65d6c3 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe(a)kernel.dk>
Date: Thu, 18 Sep 2025 10:21:14 -0600
Subject: [PATCH] io_uring: include dying ring in task_work "should cancel"
state
When running task_work for an exiting task, rather than perform the
issue retry attempt, the task_work is canceled. However, this isn't
done for a ring that has been closed. This can lead to requests being
successfully completed post the ring being closed, which is somewhat
confusing and surprising to an application.
Rather than just check the task exit state, also include the ring
ref state in deciding whether or not to terminate a given request when
run from task_work.
Cc: stable(a)vger.kernel.org # 6.1+
Link: https://github.com/axboe/liburing/discussions/1459
Reported-by: Benedek Thaler <thaler(a)thaler.hu>
Signed-off-by: Jens Axboe <axboe(a)kernel.dk>
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 93633613a165..bcec12256f34 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1406,8 +1406,10 @@ static void io_req_task_cancel(struct io_kiocb *req, io_tw_token_t tw)
void io_req_task_submit(struct io_kiocb *req, io_tw_token_t tw)
{
- io_tw_lock(req->ctx, tw);
- if (unlikely(io_should_terminate_tw()))
+ struct io_ring_ctx *ctx = req->ctx;
+
+ io_tw_lock(ctx, tw);
+ if (unlikely(io_should_terminate_tw(ctx)))
io_req_defer_failed(req, -EFAULT);
else if (req->flags & REQ_F_FORCE_ASYNC)
io_queue_iowq(req);
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index abc6de227f74..1880902be6fd 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -476,9 +476,9 @@ static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
* 2) PF_KTHREAD is set, in which case the invoker of the task_work is
* our fallback task_work.
*/
-static inline bool io_should_terminate_tw(void)
+static inline bool io_should_terminate_tw(struct io_ring_ctx *ctx)
{
- return current->flags & (PF_KTHREAD | PF_EXITING);
+ return (current->flags & (PF_KTHREAD | PF_EXITING)) || percpu_ref_is_dying(&ctx->refs);
}
static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res)
diff --git a/io_uring/poll.c b/io_uring/poll.c
index c786e587563b..6090a26975d4 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -224,7 +224,7 @@ static int io_poll_check_events(struct io_kiocb *req, io_tw_token_t tw)
{
int v;
- if (unlikely(io_should_terminate_tw()))
+ if (unlikely(io_should_terminate_tw(req->ctx)))
return -ECANCELED;
do {
diff --git a/io_uring/timeout.c b/io_uring/timeout.c
index 7f13bfa9f2b6..17e3aab0af36 100644
--- a/io_uring/timeout.c
+++ b/io_uring/timeout.c
@@ -324,7 +324,7 @@ static void io_req_task_link_timeout(struct io_kiocb *req, io_tw_token_t tw)
int ret;
if (prev) {
- if (!io_should_terminate_tw()) {
+ if (!io_should_terminate_tw(req->ctx)) {
struct io_cancel_data cd = {
.ctx = req->ctx,
.data = prev->cqe.user_data,
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 053bac89b6c0..213716e10d70 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -118,7 +118,7 @@ static void io_uring_cmd_work(struct io_kiocb *req, io_tw_token_t tw)
struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
unsigned int flags = IO_URING_F_COMPLETE_DEFER;
- if (io_should_terminate_tw())
+ if (io_should_terminate_tw(req->ctx))
flags |= IO_URING_F_TASK_DEAD;
/* task_work executor checks the deffered list completion */
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(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 3539b1467e94336d5854ebf976d9627bfb65d6c3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092127-emit-dean-5272@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3539b1467e94336d5854ebf976d9627bfb65d6c3 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe(a)kernel.dk>
Date: Thu, 18 Sep 2025 10:21:14 -0600
Subject: [PATCH] io_uring: include dying ring in task_work "should cancel"
state
When running task_work for an exiting task, rather than perform the
issue retry attempt, the task_work is canceled. However, this isn't
done for a ring that has been closed. This can lead to requests being
successfully completed post the ring being closed, which is somewhat
confusing and surprising to an application.
Rather than just check the task exit state, also include the ring
ref state in deciding whether or not to terminate a given request when
run from task_work.
Cc: stable(a)vger.kernel.org # 6.1+
Link: https://github.com/axboe/liburing/discussions/1459
Reported-by: Benedek Thaler <thaler(a)thaler.hu>
Signed-off-by: Jens Axboe <axboe(a)kernel.dk>
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 93633613a165..bcec12256f34 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1406,8 +1406,10 @@ static void io_req_task_cancel(struct io_kiocb *req, io_tw_token_t tw)
void io_req_task_submit(struct io_kiocb *req, io_tw_token_t tw)
{
- io_tw_lock(req->ctx, tw);
- if (unlikely(io_should_terminate_tw()))
+ struct io_ring_ctx *ctx = req->ctx;
+
+ io_tw_lock(ctx, tw);
+ if (unlikely(io_should_terminate_tw(ctx)))
io_req_defer_failed(req, -EFAULT);
else if (req->flags & REQ_F_FORCE_ASYNC)
io_queue_iowq(req);
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index abc6de227f74..1880902be6fd 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -476,9 +476,9 @@ static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
* 2) PF_KTHREAD is set, in which case the invoker of the task_work is
* our fallback task_work.
*/
-static inline bool io_should_terminate_tw(void)
+static inline bool io_should_terminate_tw(struct io_ring_ctx *ctx)
{
- return current->flags & (PF_KTHREAD | PF_EXITING);
+ return (current->flags & (PF_KTHREAD | PF_EXITING)) || percpu_ref_is_dying(&ctx->refs);
}
static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res)
diff --git a/io_uring/poll.c b/io_uring/poll.c
index c786e587563b..6090a26975d4 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -224,7 +224,7 @@ static int io_poll_check_events(struct io_kiocb *req, io_tw_token_t tw)
{
int v;
- if (unlikely(io_should_terminate_tw()))
+ if (unlikely(io_should_terminate_tw(req->ctx)))
return -ECANCELED;
do {
diff --git a/io_uring/timeout.c b/io_uring/timeout.c
index 7f13bfa9f2b6..17e3aab0af36 100644
--- a/io_uring/timeout.c
+++ b/io_uring/timeout.c
@@ -324,7 +324,7 @@ static void io_req_task_link_timeout(struct io_kiocb *req, io_tw_token_t tw)
int ret;
if (prev) {
- if (!io_should_terminate_tw()) {
+ if (!io_should_terminate_tw(req->ctx)) {
struct io_cancel_data cd = {
.ctx = req->ctx,
.data = prev->cqe.user_data,
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 053bac89b6c0..213716e10d70 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -118,7 +118,7 @@ static void io_uring_cmd_work(struct io_kiocb *req, io_tw_token_t tw)
struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
unsigned int flags = IO_URING_F_COMPLETE_DEFER;
- if (io_should_terminate_tw())
+ if (io_should_terminate_tw(req->ctx))
flags |= IO_URING_F_TASK_DEAD;
/* task_work executor checks the deffered list completion */
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(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x a09a8a1fbb374e0053b97306da9dbc05bd384685
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092110-music-knoll-828f@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a09a8a1fbb374e0053b97306da9dbc05bd384685 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hughd(a)google.com>
Date: Mon, 8 Sep 2025 15:16:53 -0700
Subject: [PATCH] mm/gup: local lru_add_drain() to avoid lru_add_drain_all()
In many cases, if collect_longterm_unpinnable_folios() does need to drain
the LRU cache to release a reference, the cache in question is on this
same CPU, and much more efficiently drained by a preliminary local
lru_add_drain(), than the later cross-CPU lru_add_drain_all().
Marked for stable, to counter the increase in lru_add_drain_all()s from
"mm/gup: check ref_count instead of lru before migration". Note for clean
backports: can take 6.16 commit a03db236aebf ("gup: optimize longterm
pin_user_pages() for large folio") first.
Link: https://lkml.kernel.org/r/66f2751f-283e-816d-9530-765db7edc465@google.com
Signed-off-by: Hugh Dickins <hughd(a)google.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar(a)kernel.org>
Cc: Axel Rasmussen <axelrasmussen(a)google.com>
Cc: Chris Li <chrisl(a)kernel.org>
Cc: Christoph Hellwig <hch(a)infradead.org>
Cc: Jason Gunthorpe <jgg(a)ziepe.ca>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: John Hubbard <jhubbard(a)nvidia.com>
Cc: Keir Fraser <keirf(a)google.com>
Cc: Konstantin Khlebnikov <koct9i(a)gmail.com>
Cc: Li Zhe <lizhe.67(a)bytedance.com>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: Peter Xu <peterx(a)redhat.com>
Cc: Rik van Riel <riel(a)surriel.com>
Cc: Shivank Garg <shivankg(a)amd.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: Wei Xu <weixugc(a)google.com>
Cc: Will Deacon <will(a)kernel.org>
Cc: yangge <yangge1116(a)126.com>
Cc: Yuanchu Xie <yuanchu(a)google.com>
Cc: Yu Zhao <yuzhao(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/gup.c b/mm/gup.c
index 82aec6443c0a..b47066a54f52 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2287,8 +2287,8 @@ static unsigned long collect_longterm_unpinnable_folios(
struct pages_or_folios *pofs)
{
unsigned long collected = 0;
- bool drain_allow = true;
struct folio *folio;
+ int drained = 0;
long i = 0;
for (folio = pofs_get_folio(pofs, i); folio;
@@ -2307,10 +2307,17 @@ static unsigned long collect_longterm_unpinnable_folios(
continue;
}
- if (drain_allow && folio_ref_count(folio) !=
- folio_expected_ref_count(folio) + 1) {
+ if (drained == 0 &&
+ folio_ref_count(folio) !=
+ folio_expected_ref_count(folio) + 1) {
+ lru_add_drain();
+ drained = 1;
+ }
+ if (drained == 1 &&
+ folio_ref_count(folio) !=
+ folio_expected_ref_count(folio) + 1) {
lru_add_drain_all();
- drain_allow = false;
+ drained = 2;
}
if (!folio_isolate_lru(folio))
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(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092108-drinking-sloped-1caa@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert(a)gondor.apana.org.au>
Date: Tue, 16 Sep 2025 17:20:59 +0800
Subject: [PATCH] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
Issuing two writes to the same af_alg socket is bogus as the
data will be interleaved in an unpredictable fashion. Furthermore,
concurrent writes may create inconsistencies in the internal
socket state.
Disallow this by adding a new ctx->write field that indiciates
exclusive ownership for writing.
Fixes: 8ff590903d5 ("crypto: algif_skcipher - User-space interface for skcipher operations")
Reported-by: Muhammad Alifa Ramdhan <ramdhan(a)starlabs.sg>
Reported-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 407f2c238f2c..ca6fdcc6c54a 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -970,6 +970,12 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
}
lock_sock(sk);
+ if (ctx->write) {
+ release_sock(sk);
+ return -EBUSY;
+ }
+ ctx->write = true;
+
if (ctx->init && !ctx->more) {
if (ctx->used) {
err = -EINVAL;
@@ -1105,6 +1111,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
unlock:
af_alg_data_wakeup(sk);
+ ctx->write = false;
release_sock(sk);
return copied ?: err;
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index f7b3b93f3a49..0c70f3a55575 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -135,6 +135,7 @@ struct af_alg_async_req {
* SG?
* @enc: Cryptographic operation to be performed when
* recvmsg is invoked.
+ * @write: True if we are in the middle of a write.
* @init: True if metadata has been sent.
* @len: Length of memory allocated for this data structure.
* @inflight: Non-zero when AIO requests are in flight.
@@ -151,10 +152,11 @@ struct af_alg_ctx {
size_t used;
atomic_t rcvused;
- bool more;
- bool merge;
- bool enc;
- bool init;
+ u32 more:1,
+ merge:1,
+ enc:1,
+ write:1,
+ init:1;
unsigned int len;
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092108-unmarked-tropical-1899@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert(a)gondor.apana.org.au>
Date: Tue, 16 Sep 2025 17:20:59 +0800
Subject: [PATCH] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
Issuing two writes to the same af_alg socket is bogus as the
data will be interleaved in an unpredictable fashion. Furthermore,
concurrent writes may create inconsistencies in the internal
socket state.
Disallow this by adding a new ctx->write field that indiciates
exclusive ownership for writing.
Fixes: 8ff590903d5 ("crypto: algif_skcipher - User-space interface for skcipher operations")
Reported-by: Muhammad Alifa Ramdhan <ramdhan(a)starlabs.sg>
Reported-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 407f2c238f2c..ca6fdcc6c54a 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -970,6 +970,12 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
}
lock_sock(sk);
+ if (ctx->write) {
+ release_sock(sk);
+ return -EBUSY;
+ }
+ ctx->write = true;
+
if (ctx->init && !ctx->more) {
if (ctx->used) {
err = -EINVAL;
@@ -1105,6 +1111,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
unlock:
af_alg_data_wakeup(sk);
+ ctx->write = false;
release_sock(sk);
return copied ?: err;
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index f7b3b93f3a49..0c70f3a55575 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -135,6 +135,7 @@ struct af_alg_async_req {
* SG?
* @enc: Cryptographic operation to be performed when
* recvmsg is invoked.
+ * @write: True if we are in the middle of a write.
* @init: True if metadata has been sent.
* @len: Length of memory allocated for this data structure.
* @inflight: Non-zero when AIO requests are in flight.
@@ -151,10 +152,11 @@ struct af_alg_ctx {
size_t used;
atomic_t rcvused;
- bool more;
- bool merge;
- bool enc;
- bool init;
+ u32 more:1,
+ merge:1,
+ enc:1,
+ write:1,
+ init:1;
unsigned int len;
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(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092107-crowbar-posting-c6ba@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert(a)gondor.apana.org.au>
Date: Tue, 16 Sep 2025 17:20:59 +0800
Subject: [PATCH] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
Issuing two writes to the same af_alg socket is bogus as the
data will be interleaved in an unpredictable fashion. Furthermore,
concurrent writes may create inconsistencies in the internal
socket state.
Disallow this by adding a new ctx->write field that indiciates
exclusive ownership for writing.
Fixes: 8ff590903d5 ("crypto: algif_skcipher - User-space interface for skcipher operations")
Reported-by: Muhammad Alifa Ramdhan <ramdhan(a)starlabs.sg>
Reported-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 407f2c238f2c..ca6fdcc6c54a 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -970,6 +970,12 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
}
lock_sock(sk);
+ if (ctx->write) {
+ release_sock(sk);
+ return -EBUSY;
+ }
+ ctx->write = true;
+
if (ctx->init && !ctx->more) {
if (ctx->used) {
err = -EINVAL;
@@ -1105,6 +1111,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
unlock:
af_alg_data_wakeup(sk);
+ ctx->write = false;
release_sock(sk);
return copied ?: err;
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index f7b3b93f3a49..0c70f3a55575 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -135,6 +135,7 @@ struct af_alg_async_req {
* SG?
* @enc: Cryptographic operation to be performed when
* recvmsg is invoked.
+ * @write: True if we are in the middle of a write.
* @init: True if metadata has been sent.
* @len: Length of memory allocated for this data structure.
* @inflight: Non-zero when AIO requests are in flight.
@@ -151,10 +152,11 @@ struct af_alg_ctx {
size_t used;
atomic_t rcvused;
- bool more;
- bool merge;
- bool enc;
- bool init;
+ u32 more:1,
+ merge:1,
+ enc:1,
+ write:1,
+ init:1;
unsigned int len;
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 7f830e126dc357fc086905ce9730140fd4528d66
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092126-fabulous-despair-ac21@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7f830e126dc357fc086905ce9730140fd4528d66 Mon Sep 17 00:00:00 2001
From: Tom Lendacky <thomas.lendacky(a)amd.com>
Date: Mon, 15 Sep 2025 11:04:12 -0500
Subject: [PATCH] x86/sev: Guard sev_evict_cache() with CONFIG_AMD_MEM_ENCRYPT
The sev_evict_cache() is guest-related code and should be guarded by
CONFIG_AMD_MEM_ENCRYPT, not CONFIG_KVM_AMD_SEV.
CONFIG_AMD_MEM_ENCRYPT=y is required for a guest to run properly as an SEV-SNP
guest, but a guest kernel built with CONFIG_KVM_AMD_SEV=n would get the stub
function of sev_evict_cache() instead of the version that performs the actual
eviction. Move the function declarations under the appropriate #ifdef.
Fixes: 7b306dfa326f ("x86/sev: Evict cache lines during SNP memory validation")
Signed-off-by: Tom Lendacky <thomas.lendacky(a)amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: stable(a)kernel.org # 6.16.x
Link: https://lore.kernel.org/r/70e38f2c4a549063de54052c9f64929705313526.17577089…
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 02236962fdb1..465b19fd1a2d 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -562,6 +562,24 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
extern struct ghcb *boot_ghcb;
+static inline void sev_evict_cache(void *va, int npages)
+{
+ volatile u8 val __always_unused;
+ u8 *bytes = va;
+ int page_idx;
+
+ /*
+ * For SEV guests, a read from the first/last cache-lines of a 4K page
+ * using the guest key is sufficient to cause a flush of all cache-lines
+ * associated with that 4K page without incurring all the overhead of a
+ * full CLFLUSH sequence.
+ */
+ for (page_idx = 0; page_idx < npages; page_idx++) {
+ val = bytes[page_idx * PAGE_SIZE];
+ val = bytes[page_idx * PAGE_SIZE + PAGE_SIZE - 1];
+ }
+}
+
#else /* !CONFIG_AMD_MEM_ENCRYPT */
#define snp_vmpl 0
@@ -605,6 +623,7 @@ static inline int snp_send_guest_request(struct snp_msg_desc *mdesc,
static inline int snp_svsm_vtpm_send_command(u8 *buffer) { return -ENODEV; }
static inline void __init snp_secure_tsc_prepare(void) { }
static inline void __init snp_secure_tsc_init(void) { }
+static inline void sev_evict_cache(void *va, int npages) {}
#endif /* CONFIG_AMD_MEM_ENCRYPT */
@@ -619,24 +638,6 @@ int rmp_make_shared(u64 pfn, enum pg_level level);
void snp_leak_pages(u64 pfn, unsigned int npages);
void kdump_sev_callback(void);
void snp_fixup_e820_tables(void);
-
-static inline void sev_evict_cache(void *va, int npages)
-{
- volatile u8 val __always_unused;
- u8 *bytes = va;
- int page_idx;
-
- /*
- * For SEV guests, a read from the first/last cache-lines of a 4K page
- * using the guest key is sufficient to cause a flush of all cache-lines
- * associated with that 4K page without incurring all the overhead of a
- * full CLFLUSH sequence.
- */
- for (page_idx = 0; page_idx < npages; page_idx++) {
- val = bytes[page_idx * PAGE_SIZE];
- val = bytes[page_idx * PAGE_SIZE + PAGE_SIZE - 1];
- }
-}
#else
static inline bool snp_probe_rmptable_info(void) { return false; }
static inline int snp_rmptable_init(void) { return -ENOSYS; }
@@ -652,7 +653,6 @@ static inline int rmp_make_shared(u64 pfn, enum pg_level level) { return -ENODEV
static inline void snp_leak_pages(u64 pfn, unsigned int npages) {}
static inline void kdump_sev_callback(void) { }
static inline void snp_fixup_e820_tables(void) {}
-static inline void sev_evict_cache(void *va, int npages) {}
#endif
#endif
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(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 7f830e126dc357fc086905ce9730140fd4528d66
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092125-stitch-starting-35cb@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7f830e126dc357fc086905ce9730140fd4528d66 Mon Sep 17 00:00:00 2001
From: Tom Lendacky <thomas.lendacky(a)amd.com>
Date: Mon, 15 Sep 2025 11:04:12 -0500
Subject: [PATCH] x86/sev: Guard sev_evict_cache() with CONFIG_AMD_MEM_ENCRYPT
The sev_evict_cache() is guest-related code and should be guarded by
CONFIG_AMD_MEM_ENCRYPT, not CONFIG_KVM_AMD_SEV.
CONFIG_AMD_MEM_ENCRYPT=y is required for a guest to run properly as an SEV-SNP
guest, but a guest kernel built with CONFIG_KVM_AMD_SEV=n would get the stub
function of sev_evict_cache() instead of the version that performs the actual
eviction. Move the function declarations under the appropriate #ifdef.
Fixes: 7b306dfa326f ("x86/sev: Evict cache lines during SNP memory validation")
Signed-off-by: Tom Lendacky <thomas.lendacky(a)amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: stable(a)kernel.org # 6.16.x
Link: https://lore.kernel.org/r/70e38f2c4a549063de54052c9f64929705313526.17577089…
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 02236962fdb1..465b19fd1a2d 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -562,6 +562,24 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
extern struct ghcb *boot_ghcb;
+static inline void sev_evict_cache(void *va, int npages)
+{
+ volatile u8 val __always_unused;
+ u8 *bytes = va;
+ int page_idx;
+
+ /*
+ * For SEV guests, a read from the first/last cache-lines of a 4K page
+ * using the guest key is sufficient to cause a flush of all cache-lines
+ * associated with that 4K page without incurring all the overhead of a
+ * full CLFLUSH sequence.
+ */
+ for (page_idx = 0; page_idx < npages; page_idx++) {
+ val = bytes[page_idx * PAGE_SIZE];
+ val = bytes[page_idx * PAGE_SIZE + PAGE_SIZE - 1];
+ }
+}
+
#else /* !CONFIG_AMD_MEM_ENCRYPT */
#define snp_vmpl 0
@@ -605,6 +623,7 @@ static inline int snp_send_guest_request(struct snp_msg_desc *mdesc,
static inline int snp_svsm_vtpm_send_command(u8 *buffer) { return -ENODEV; }
static inline void __init snp_secure_tsc_prepare(void) { }
static inline void __init snp_secure_tsc_init(void) { }
+static inline void sev_evict_cache(void *va, int npages) {}
#endif /* CONFIG_AMD_MEM_ENCRYPT */
@@ -619,24 +638,6 @@ int rmp_make_shared(u64 pfn, enum pg_level level);
void snp_leak_pages(u64 pfn, unsigned int npages);
void kdump_sev_callback(void);
void snp_fixup_e820_tables(void);
-
-static inline void sev_evict_cache(void *va, int npages)
-{
- volatile u8 val __always_unused;
- u8 *bytes = va;
- int page_idx;
-
- /*
- * For SEV guests, a read from the first/last cache-lines of a 4K page
- * using the guest key is sufficient to cause a flush of all cache-lines
- * associated with that 4K page without incurring all the overhead of a
- * full CLFLUSH sequence.
- */
- for (page_idx = 0; page_idx < npages; page_idx++) {
- val = bytes[page_idx * PAGE_SIZE];
- val = bytes[page_idx * PAGE_SIZE + PAGE_SIZE - 1];
- }
-}
#else
static inline bool snp_probe_rmptable_info(void) { return false; }
static inline int snp_rmptable_init(void) { return -ENOSYS; }
@@ -652,7 +653,6 @@ static inline int rmp_make_shared(u64 pfn, enum pg_level level) { return -ENODEV
static inline void snp_leak_pages(u64 pfn, unsigned int npages) {}
static inline void kdump_sev_callback(void) { }
static inline void snp_fixup_e820_tables(void) {}
-static inline void sev_evict_cache(void *va, int npages) {}
#endif
#endif