From a9516936e5e4798a2474af2e406e2e3784d2bbb7 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 10 Feb 2021 15:25:37 +0800 Subject: [PATCH] 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 Git-commit: fc961522ddbdf00254dd03b677627139cc1f68bc Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Signed-off-by: lixiang --- fs/exfat/nls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c index 5c411c890ab8..915daad3b97b 100644 --- a/fs/exfat/nls.c +++ b/fs/exfat/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)