FAILED: patch "[PATCH] mm/madvise: handle madvise_lock() failure during race" failed to apply to 6.15-stable tree

FAILED: patch "[PATCH] mm/madvise: handle madvise_lock() failure during race" failed to apply to 6.15-stable tree

[gregkh]

The patch below does not apply to the 6.15-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-6.15.y
git checkout FETCH_HEAD
git cherry-pick -x 9c49e5d09f076001e05537734d7df002162eb2b5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025062020-gambling-poker-8b0c@gregkh' --subject-prefix 'PATCH 6.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9c49e5d09f076001e05537734d7df002162eb2b5 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj@kernel.org>
Date: Mon, 2 Jun 2025 10:49:26 -0700
Subject: [PATCH] mm/madvise: handle madvise_lock() failure during race
 unwinding

When unwinding race on -ERESTARTNOINTR handling of process_madvise(),
madvise_lock() failure is ignored.  Check the failure and abort remaining
works in the case.

Link: https://lkml.kernel.org/r/20250602174926.1074-1-sj@kernel.org
Fixes: 4000e3d0a367 ("mm/madvise: remove redundant mmap_lock operations from process_madvise()")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Barry Song <21cnbao@gmail.com>
Closes: https://lore.kernel.org/CAGsJ_4xJXXO0G+4BizhohSZ4yDteziPw43_uF8nPXPWxUVChzw@mail.gmail.com
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Barry Song <baohua@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/madvise.c b/mm/madvise.c
index 8433ac9b27e0..5f7a66a1617e 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1881,7 +1881,9 @@ static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
 			/* Drop and reacquire lock to unwind race. */
 			madvise_finish_tlb(&madv_behavior);
 			madvise_unlock(mm, behavior);
-			madvise_lock(mm, behavior);
+			ret = madvise_lock(mm, behavior);
+			if (ret)
+				goto out;
 			madvise_init_tlb(&madv_behavior, mm);
 			continue;
 		}
@@ -1892,6 +1894,7 @@ static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
 	madvise_finish_tlb(&madv_behavior);
 	madvise_unlock(mm, behavior);
 
+out:
 	ret = (total_len - iov_iter_count(iter)) ? : ret;
 
 	return ret;

[PATCH 6.15.y] mm/madvise: handle madvise_lock() failure during race unwinding

[SeongJae Park]

When unwinding race on -ERESTARTNOINTR handling of process_madvise(),
madvise_lock() failure is ignored.  Check the failure and abort remaining
works in the case.

Link: https://lkml.kernel.org/r/20250602174926.1074-1-sj@kernel.org
Fixes: 4000e3d0a367 ("mm/madvise: remove redundant mmap_lock operations from process_madvise()")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Barry Song <21cnbao@gmail.com>
Closes: https://lore.kernel.org/CAGsJ_4xJXXO0G+4BizhohSZ4yDteziPw43_uF8nPXPWxUVChzw@mail.gmail.com
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Barry Song <baohua@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 9c49e5d09f076001e05537734d7df002162eb2b5)
---
 mm/madvise.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index b17f684322ad..69510e737783 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1830,7 +1830,9 @@ static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
 
 			/* Drop and reacquire lock to unwind race. */
 			madvise_unlock(mm, behavior);
-			madvise_lock(mm, behavior);
+			ret = madvise_lock(mm, behavior);
+			if (ret)
+				goto out;
 			continue;
 		}
 		if (ret < 0)
@@ -1839,6 +1841,7 @@ static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
 	}
 	madvise_unlock(mm, behavior);
 
+out:
 	ret = (total_len - iov_iter_count(iter)) ? : ret;
 
 	return ret;
-- 
2.39.5

Re: [PATCH 6.15.y] mm/madvise: handle madvise_lock() failure during race unwinding

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: 9c49e5d09f076001e05537734d7df002162eb2b5

Note: The patch differs from the upstream commit:
---
1:  9c49e5d09f076 ! 1:  0f9b85d494656 mm/madvise: handle madvise_lock() failure during race unwinding
    @@ Commit message
         Cc: Vlastimil Babka <vbabka@suse.cz>
         Cc: <stable@vger.kernel.org>
         Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    +    (cherry picked from commit 9c49e5d09f076001e05537734d7df002162eb2b5)
     
      ## mm/madvise.c ##
     @@ mm/madvise.c: static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
    + 
      			/* Drop and reacquire lock to unwind race. */
    - 			madvise_finish_tlb(&madv_behavior);
      			madvise_unlock(mm, behavior);
     -			madvise_lock(mm, behavior);
     +			ret = madvise_lock(mm, behavior);
     +			if (ret)
     +				goto out;
    - 			madvise_init_tlb(&madv_behavior, mm);
      			continue;
      		}
    + 		if (ret < 0)
     @@ mm/madvise.c: static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
    - 	madvise_finish_tlb(&madv_behavior);
    + 	}
      	madvise_unlock(mm, behavior);
      
     +out:
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.15.y       |  Success    |  Success   |