From fc961522ddbdf00254dd03b677627139cc1f68bc Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 8 Jun 2020 17:16:29 +0300 Subject: [Backport fc961522ddbd] exfat: Fix potential use after free in exfat_load_upcase_table() This code calls brelse(bh) and then dereferences "bh" on the next line resulting in a possible use after free. The brelse() should just be moved down a line. Fixes: b676fdbcf4c8 ("exfat: standardize checksum calculation") Signed-off-by: Dan Carpenter Signed-off-by: Namjae Jeon --- src/nls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/nls.c b/src/nls.c index c1ec05695497445934ac8f2d537ccd131e5d7f5c..57b5a7a4d1f7a18b1854348bd6841ea7bc9c466a 100644 --- a/src/nls.c +++ b/src/nls.c @@ -692,8 +692,8 @@ static int exfat_load_upcase_table(struct super_block *sb, index++; } } - brelse(bh); chksum = exfat_calc_chksum32(bh->b_data, i, chksum, CS_DEFAULT); + brelse(bh); } if (index >= 0xFFFF && utbl_checksum == chksum) -- 2.31.1