The patch titled
Subject: squashfs: fix buffer release race condition in readahead code
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
squashfs-fix-buffer-release-race-condition-in-readahead-code.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/squashfs-fix-buffer-release-race-condition-in-readahead-code.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: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
Subject: squashfs: fix buffer release race condition in readahead code
Date: Thu, 20 Oct 2022 23:36:16 +0100
Fix a buffer release race condition, where the error value was used after
release.
Link: https://lkml.kernel.org/r/20221020223616.7571-4-phillip@xxxxxxxxxxxxxxx
Fixes: b09a7a036d20 ("squashfs: support reading fragments in readahead call")
Signed-off-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
Cc: Dimitri John Ledkov <dimitri.ledkov@xxxxxxxxxxxxx>
Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Cc: Mirsad Goran Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
Cc: Slade Watkins <srw@xxxxxxxxxxxxxxxx>
Cc: Thorsten Leemhuis <regressions@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/squashfs/file.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/fs/squashfs/file.c~squashfs-fix-buffer-release-race-condition-in-readahead-code
+++ a/fs/squashfs/file.c
@@ -506,8 +506,9 @@ static int squashfs_readahead_fragment(s
squashfs_i(inode)->fragment_size);
struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
unsigned int n, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
+ int error = buffer->error;
- if (buffer->error)
+ if (error)
goto out;
expected += squashfs_i(inode)->fragment_offset;
@@ -529,7 +530,7 @@ static int squashfs_readahead_fragment(s
out:
squashfs_cache_put(buffer);
- return buffer->error;
+ return error;
}
static void squashfs_readahead(struct readahead_control *ractl)
_
Patches currently in -mm which might be from phillip@xxxxxxxxxxxxxxx are
squashfs-fix-read-regression-introduced-in-readahead-code.patch
squashfs-fix-extending-readahead-beyond-end-of-file.patch
squashfs-fix-buffer-release-race-condition-in-readahead-code.patch
