From e11c4e088be4c39d17f304fcf331670891905f42 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Thu, 20 Oct 2022 23:36:16 +0100 Subject: [PATCH] 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: b09a7a036d20 ("squashfs: support reading fragments in readahead call") Signed-off-by: Phillip Lougher Tested-by: Bagas Sanjaya Reported-by: Marc Miltenberger Cc: Dimitri John Ledkov Cc: Hsin-Yi Wang Cc: Mirsad Goran Todorovac Cc: Slade Watkins Cc: Thorsten Leemhuis Cc: Signed-off-by: Andrew Morton --- fs/squashfs/file.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index f0afd4d6fd30..8ba8c4c50770 100644 --- a/fs/squashfs/file.c +++ b/fs/squashfs/file.c @@ -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)