Commit e11c4e08 authored by Phillip Lougher's avatar Phillip Lougher Committed by Andrew Morton
Browse files

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: b09a7a03 ("squashfs: support reading fragments in readahead call")
Signed-off-by: default avatarPhillip Lougher <phillip@squashfs.org.uk>
Tested-by: default avatarBagas Sanjaya <bagasdotme@gmail.com>
Reported-by: default avatarMarc 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c9199de8

fs/squashfs/file.c

+3 −2
Original line number Diff line number Diff line
@@ -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)