From de0bb97aff6743f71abb8ec581238e2bdae9cdd1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 26 Apr 2006 07:26:09 +0100 Subject: [PATCH] [PATCH] forgotten ->b_data in memcpy() call in ext3/resize.c (oopsable) sbi->s_group_desc is an array of pointers to buffer_head. memcpy() of buffer size from address of buffer_head is a bad idea - it will generate junk in any case, may oops if buffer_head is close to the end of slab page and next page is not mapped and isn't what was intended there. IOW, ->b_data is missing in that call. Fortunately, result doesn't go into the primary on-disk data structures, so only backup ones get crap written to them; that had allowed this bug to remain unnoticed until now. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds --- fs/ext3/resize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c index c5ffa8523968..8aac5334680d 100644 --- a/fs/ext3/resize.c +++ b/fs/ext3/resize.c @@ -213,7 +213,7 @@ static int setup_new_group_blocks(struct super_block *sb, goto exit_bh; } lock_buffer(bh); - memcpy(gdb->b_data, sbi->s_group_desc[i], bh->b_size); + memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, bh->b_size); set_buffer_uptodate(gdb); unlock_buffer(bh); ext3_journal_dirty_metadata(handle, gdb); -- 2.20.1