The patch titled
Subject: filemap: fix the conditional folio_put in filemap_fault
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
filemap-fix-the-conditional-folio_put-in-filemap_fault.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/filemap-fix-the-conditional-folio_put-in-filemap_fault.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Christoph Hellwig <hch@xxxxxx>
Subject: filemap: fix the conditional folio_put in filemap_fault
Date: Wed, 3 May 2023 17:45:25 +0200
folio can't be NULL here now that __filemap_get_folio returns an ERR_PTR.
Remove the conditional folio_put after the out_retry label and add a new
label for the cases where we have a valid folio.
Link: https://lkml.kernel.org/r/20230503154526.1223095-1-hch@xxxxxx
Fixes: 66dabbb65d67 ("mm: return an ERR_PTR from __filemap_get_folio")
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: syzbot+48011b86c8ea329af1b9@xxxxxxxxxxxxxxxxxxxxxxxxx
Reviewed-by: Jan Kara <jack@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/mm/filemap.c~filemap-fix-the-conditional-folio_put-in-filemap_fault
+++ a/mm/filemap.c
@@ -3298,7 +3298,7 @@ retry_find:
}
if (!lock_folio_maybe_drop_mmap(vmf, folio, &fpin))
- goto out_retry;
+ goto out_retry_put_folio;
/* Did it get truncated? */
if (unlikely(folio->mapping != mapping)) {
@@ -3334,7 +3334,7 @@ retry_find:
*/
if (fpin) {
folio_unlock(folio);
- goto out_retry;
+ goto out_retry_put_folio;
}
if (mapping_locked)
filemap_invalidate_unlock_shared(mapping);
@@ -3363,7 +3363,7 @@ page_not_uptodate:
fpin = maybe_unlock_mmap_for_io(vmf, fpin);
error = filemap_read_folio(file, mapping->a_ops->read_folio, folio);
if (fpin)
- goto out_retry;
+ goto out_retry_put_folio;
folio_put(folio);
if (!error || error == AOP_TRUNCATED_PAGE)
@@ -3372,14 +3372,14 @@ page_not_uptodate:
return VM_FAULT_SIGBUS;
+out_retry_put_folio:
+ folio_put(folio);
out_retry:
/*
* We dropped the mmap_lock, we need to return to the fault handler to
* re-find the vma and come back and find our hopefully still populated
* page.
*/
- if (folio)
- folio_put(folio);
if (mapping_locked)
filemap_invalidate_unlock_shared(mapping);
if (fpin)
_
Patches currently in -mm which might be from hch@xxxxxx are
filemap-fix-the-conditional-folio_put-in-filemap_fault.patch
afs-fix-the-afs_dir_get_folio-return-value.patch
