FAILED: patch "[PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"" failed to apply to 6.1-stable tree

[gregkh]

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 d1aa0c04294e29883d65eac6c2f72fe95cc7c049
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024111701-film-pantyhose-59de@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From d1aa0c04294e29883d65eac6c2f72fe95cc7c049 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Fri, 15 Nov 2024 16:57:24 -0800
Subject: [PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"

Revert d949d1d14fa2 ("mm: shmem: fix data-race in shmem_getattr()") as
suggested by Chuck [1].  It is causing deadlocks when accessing tmpfs over
NFS.

As Hugh commented, "added just to silence a syzbot sanitizer splat: added
where there has never been any practical problem".

Link: https://lkml.kernel.org/r/ZzdxKF39VEmXSSyN@tissot.1015granger.net [1]
Fixes: d949d1d14fa2 ("mm: shmem: fix data-race in shmem_getattr()")
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeongjun Park <aha310510@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/shmem.c b/mm/shmem.c
index e87f5d6799a7..568bb290bdce 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1166,9 +1166,7 @@ static int shmem_getattr(struct mnt_idmap *idmap,
 	stat->attributes_mask |= (STATX_ATTR_APPEND |
 			STATX_ATTR_IMMUTABLE |
 			STATX_ATTR_NODUMP);
-	inode_lock_shared(inode);
 	generic_fillattr(idmap, request_mask, inode, stat);
-	inode_unlock_shared(inode);
 
 	if (shmem_huge_global_enabled(inode, 0, 0, false, NULL, 0))
 		stat->blksize = HPAGE_PMD_SIZE;

Re: FAILED: patch "[PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"" failed to apply to 6.1-stable tree

[Hugh Dickins]

On Sun, 17 Nov 2024, gregkh@linuxfoundation.org wrote:
> 
> 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 d1aa0c04294e29883d65eac6c2f72fe95cc7c049
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024111701-film-pantyhose-59de@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

For 6.1 please use this replacement patch:

From f6a8e058ad34f16109d54218c64e0c215bcc04fc Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Fri, 15 Nov 2024 16:57:24 -0800
Subject: [PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"

commit d1aa0c04294e29883d65eac6c2f72fe95cc7c049 upstream.

Revert d949d1d14fa2 ("mm: shmem: fix data-race in shmem_getattr()") as
suggested by Chuck [1].  It is causing deadlocks when accessing tmpfs over
NFS.

As Hugh commented, "added just to silence a syzbot sanitizer splat: added
where there has never been any practical problem".

Link: https://lkml.kernel.org/r/ZzdxKF39VEmXSSyN@tissot.1015granger.net [1]
Fixes: d949d1d14fa2 ("mm: shmem: fix data-race in shmem_getattr()")
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeongjun Park <aha310510@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
---
 mm/shmem.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 0e1fbc53717d..f7c08e169e42 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1086,9 +1086,7 @@ static int shmem_getattr(struct user_namespace *mnt_userns,
 	stat->attributes_mask |= (STATX_ATTR_APPEND |
 			STATX_ATTR_IMMUTABLE |
 			STATX_ATTR_NODUMP);
-	inode_lock_shared(inode);
 	generic_fillattr(&init_user_ns, inode, stat);
-	inode_unlock_shared(inode);
 
 	if (shmem_is_huge(NULL, inode, 0, false))
 		stat->blksize = HPAGE_PMD_SIZE;
-- 
2.47.0.338.g60cca15819-goog

Re: FAILED: patch "[PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"" failed to apply to 6.1-stable tree

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: d1aa0c04294e29883d65eac6c2f72fe95cc7c049

WARNING: Author mismatch between patch and upstream commit:
Backport author: Hugh Dickins <hughd@google.com>
Commit author: Andrew Morton <akpm@linux-foundation.org>

Commit in newer trees:

|-----------------|----------------------------------------------|
| 6.11.y          |  Present (different SHA1: 285505dc512d)      |
| 6.6.y           |  Present (different SHA1: 552c02da3b0f)      |
| 6.1.y           |  Not found                                   |
|-----------------|----------------------------------------------|

Note: The patch differs from the upstream commit:
---
--- -	2024-11-19 00:05:12.416053794 -0500
+++ /tmp/tmp.vwrrH0rcVj	2024-11-19 00:05:12.409155886 -0500
@@ -1,3 +1,12 @@
+For 6.1 please use this replacement patch:
+
+>From f6a8e058ad34f16109d54218c64e0c215bcc04fc Mon Sep 17 00:00:00 2001
+From: Andrew Morton <akpm@linux-foundation.org>
+Date: Fri, 15 Nov 2024 16:57:24 -0800
+Subject: [PATCH] mm: revert "mm: shmem: fix data-race in shmem_getattr()"
+
+commit d1aa0c04294e29883d65eac6c2f72fe95cc7c049 upstream.
+
 Revert d949d1d14fa2 ("mm: shmem: fix data-race in shmem_getattr()") as
 suggested by Chuck [1].  It is causing deadlocks when accessing tmpfs over
 NFS.
@@ -13,21 +22,25 @@
 Cc: Yu Zhao <yuzhao@google.com>
 Cc: <stable@vger.kernel.org>
 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Hugh Dickins <hughd@google.com>
 ---
  mm/shmem.c | 2 --
  1 file changed, 2 deletions(-)
 
 diff --git a/mm/shmem.c b/mm/shmem.c
-index e87f5d6799a7b..568bb290bdce3 100644
+index 0e1fbc53717d..f7c08e169e42 100644
 --- a/mm/shmem.c
 +++ b/mm/shmem.c
-@@ -1166,9 +1166,7 @@ static int shmem_getattr(struct mnt_idmap *idmap,
+@@ -1086,9 +1086,7 @@ static int shmem_getattr(struct user_namespace *mnt_userns,
  	stat->attributes_mask |= (STATX_ATTR_APPEND |
  			STATX_ATTR_IMMUTABLE |
  			STATX_ATTR_NODUMP);
 -	inode_lock_shared(inode);
- 	generic_fillattr(idmap, request_mask, inode, stat);
+ 	generic_fillattr(&init_user_ns, inode, stat);
 -	inode_unlock_shared(inode);
  
- 	if (shmem_huge_global_enabled(inode, 0, 0, false, NULL, 0))
+ 	if (shmem_is_huge(NULL, inode, 0, false))
  		stat->blksize = HPAGE_PMD_SIZE;
+-- 
+2.47.0.338.g60cca15819-goog
+
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |