September 2025 - Linux-stable-mirror

FAILED: patch "[PATCH] mm/gup: check ref_count instead of lru before migration" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

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 98c6d259319ecf6e8d027abd3f14b81324b8c0ad # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025092158-payee-omega-5893@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 98c6d259319ecf6e8d027abd3f14b81324b8c0ad Mon Sep 17 00:00:00 2001 From: Hugh Dickins <hughd(a)google.com> Date: Mon, 8 Sep 2025 15:15:03 -0700 Subject: [PATCH] mm/gup: check ref_count instead of lru before migration Patch series "mm: better GUP pin lru_add_drain_all()", v2. Series of lru_add_drain_all()-related patches, arising from recent mm/gup migration report from Will Deacon. This patch (of 5): Will Deacon reports:- When taking a longterm GUP pin via pin_user_pages(), __gup_longterm_locked() tries to migrate target folios that should not be longterm pinned, for example because they reside in a CMA region or movable zone. This is done by first pinning all of the target folios anyway, collecting all of the longterm-unpinnable target folios into a list, dropping the pins that were just taken and finally handing the list off to migrate_pages() for the actual migration. It is critically important that no unexpected references are held on the folios being migrated, otherwise the migration will fail and pin_user_pages() will return -ENOMEM to its caller. Unfortunately, it is relatively easy to observe migration failures when running pKVM (which uses pin_user_pages() on crosvm's virtual address space to resolve stage-2 page faults from the guest) on a 6.15-based Pixel 6 device and this results in the VM terminating prematurely. In the failure case, 'crosvm' has called mlock(MLOCK_ONFAULT) on its mapping of guest memory prior to the pinning. Subsequently, when pin_user_pages() walks the page-table, the relevant 'pte' is not present and so the faulting logic allocates a new folio, mlocks it with mlock_folio() and maps it in the page-table. Since commit 2fbb0c10d1e8 ("mm/munlock: mlock_page() munlock_page() batch by pagevec"), mlock/munlock operations on a folio (formerly page), are deferred. For example, mlock_folio() takes an additional reference on the target folio before placing it into a per-cpu 'folio_batch' for later processing by mlock_folio_batch(), which drops the refcount once the operation is complete. Processing of the batches is coupled with the LRU batch logic and can be forcefully drained with lru_add_drain_all() but as long as a folio remains unprocessed on the batch, its refcount will be elevated. This deferred batching therefore interacts poorly with the pKVM pinning scenario as we can find ourselves in a situation where the migration code fails to migrate a folio due to the elevated refcount from the pending mlock operation. Hugh Dickins adds:- !folio_test_lru() has never been a very reliable way to tell if an lru_add_drain_all() is worth calling, to remove LRU cache references to make the folio migratable: the LRU flag may be set even while the folio is held with an extra reference in a per-CPU LRU cache. 5.18 commit 2fbb0c10d1e8 may have made it more unreliable. Then 6.11 commit 33dfe9204f29 ("mm/gup: clear the LRU flag of a page before adding to LRU batch") tried to make it reliable, by moving LRU flag clearing; but missed the mlock/munlock batches, so still unreliable as reported. And it turns out to be difficult to extend 33dfe9204f29's LRU flag clearing to the mlock/munlock batches: if they do benefit from batching, mlock/munlock cannot be so effective when easily suppressed while !LRU. Instead, switch to an expected ref_count check, which was more reliable all along: some more false positives (unhelpful drains) than before, and never a guarantee that the folio will prove migratable, but better. Note on PG_private_2: ceph and nfs are still using the deprecated PG_private_2 flag, with the aid of netfs and filemap support functions. Although it is consistently matched by an increment of folio ref_count, folio_expected_ref_count() intentionally does not recognize it, and ceph folio migration currently depends on that for PG_private_2 folios to be rejected. New references to the deprecated flag are discouraged, so do not add it into the collect_longterm_unpinnable_folios() calculation: but longterm pinning of transiently PG_private_2 ceph and nfs folios (an uncommon case) may invoke a redundant lru_add_drain_all(). And this makes easy the backport to earlier releases: up to and including 6.12, btrfs also used PG_private_2, but without a ref_count increment. Note for stable backports: requires 6.16 commit 86ebd50224c0 ("mm: add folio_expected_ref_count() for reference count calculation"). Link: https://lkml.kernel.org/r/41395944-b0e3-c3ac-d648-8ddd70451d28@google.com Link: https://lkml.kernel.org/r/bd1f314a-fca1-8f19-cac0-b936c9614557@google.com Fixes: 9a4e9f3b2d73 ("mm: update get_user_pages_longterm to migrate pages allocated from CMA region") Signed-off-by: Hugh Dickins <hughd(a)google.com> Reported-by: Will Deacon <will(a)kernel.org> Closes: https://lore.kernel.org/linux-mm/20250815101858.24352-1-will@kernel.org/ Acked-by: Kiryl Shutsemau <kas(a)kernel.org> 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: 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 adffe663594d..82aec6443c0a 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2307,7 +2307,8 @@ static unsigned long collect_longterm_unpinnable_folios( continue; } - if (!folio_test_lru(folio) && drain_allow) { + if (drain_allow && folio_ref_count(folio) != + folio_expected_ref_count(folio) + 1) { lru_add_drain_all(); drain_allow = false; }

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FAILED: patch "[PATCH] samples/damon/mtier: avoid starting DAMON before" failed to apply to 6.16-stable tree

by gregkh＠linuxfoundation.org

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)

1 month, 1 week

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FAILED: patch "[PATCH] samples/damon/wsse: avoid starting DAMON before" failed to apply to 6.16-stable tree

by gregkh＠linuxfoundation.org

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;

1 month, 1 week

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FAILED: patch "[PATCH] io_uring: include dying ring in task_work "should cancel"" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

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 */

1 month, 1 week

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FAILED: patch "[PATCH] io_uring: include dying ring in task_work "should cancel"" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

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 */

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FAILED: patch "[PATCH] mm/gup: local lru_add_drain() to avoid lru_add_drain_all()" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

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))

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FAILED: patch "[PATCH] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

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;

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FAILED: patch "[PATCH] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

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;

1 month, 1 week

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FAILED: patch "[PATCH] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

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;

1 month, 1 week

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FAILED: patch "[PATCH] x86/sev: Guard sev_evict_cache() with CONFIG_AMD_MEM_ENCRYPT" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

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

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