squashfs: fix buffer release race condition in readahead code

Fix a buffer release race condition, where the error value was used after
release.

Link: https://lkml.kernel.org/r/20221020223616.7571-4-phillip@squashfs.org.uk
Fixes: b09a7a036d ("squashfs: support reading fragments in readahead call")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Slade Watkins <srw@sladewatkins.net>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Phillip Lougher 2022-10-20 23:36:16 +01:00 committed by Andrew Morton
parent c9199de82b
commit e11c4e088b

View File

@ -506,8 +506,9 @@ static int squashfs_readahead_fragment(struct page **page,
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(struct page **page,
out:
squashfs_cache_put(buffer);
return buffer->error;
return error;
}
static void squashfs_readahead(struct readahead_control *ractl)