* [PATCH] exfat: Fix pontential use after free in exfat_load_upcase_table()
@ 2020-06-08 14:16 ` Dan Carpenter
2020-06-09 0:37 ` Namjae Jeon
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2020-06-08 14:16 UTC (permalink / raw)
To: Namjae Jeon, Tetsuhiro Kohada
Cc: Sungjong Seo, linux-fsdevel, linux-kernel, kernel-janitors
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 <dan.carpenter@oracle.com>
---
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 c1ec056954974..57b5a7a4d1f7a 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)
--
2.26.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* RE: [PATCH] exfat: Fix pontential use after free in exfat_load_upcase_table()
2020-06-08 14:16 ` [PATCH] exfat: Fix pontential use after free in exfat_load_upcase_table() Dan Carpenter
@ 2020-06-09 0:37 ` Namjae Jeon
0 siblings, 0 replies; 2+ messages in thread
From: Namjae Jeon @ 2020-06-09 0:37 UTC (permalink / raw)
To: 'Dan Carpenter'
Cc: 'Sungjong Seo',
linux-fsdevel, linux-kernel, kernel-janitors,
'Tetsuhiro Kohada'
> 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 <dan.carpenter@oracle.com>
Applied. Thanks!
> ---
> 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 c1ec056954974..57b5a7a4d1f7a 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)
> --
> 2.26.2
^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-06-08 14:16 ` [PATCH] exfat: Fix pontential use after free in exfat_load_upcase_table() Dan Carpenter
2020-06-09 0:37 ` Namjae Jeon
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