Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> writes:
> utf8_unload is being called if CONFIG_UNICODE is enabled.
> The ifdef block doesn't check if utf8 encoding has been loaded
> or not before calling the utf8_unload() function.
> This is not the expected behavior since it would sometimes lead
> to unloading utf8 even before loading it.
> Hence, add a condition which will check if sb->encoding is NOT NULL
> before calling the utf8_unload().
Just to mention this used to be safe, since it was just doing a
kfree(NULL), but won't be anymore after the rest of this series.
Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
>
> Signed-off-by: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx>
> ---
>
> Changes in v3
> - Add this patch to the series which checks if utf8 encoding
> was loaded before calling uft8_unload().
>
> fs/ext4/super.c | 6 ++++--
> fs/f2fs/super.c | 9 ++++++---
> 2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index ad34a3727..e438d14f9 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1259,7 +1259,8 @@ static void ext4_put_super(struct super_block *sb)
> fs_put_dax(sbi->s_daxdev);
> fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
> #ifdef CONFIG_UNICODE
> - utf8_unload(sb->s_encoding);
> + if (sb->s_encoding)
> + utf8_unload(sb->s_encoding);
> #endif
> kfree(sbi);
> }
> @@ -5165,7 +5166,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> crypto_free_shash(sbi->s_chksum_driver);
>
> #ifdef CONFIG_UNICODE
> - utf8_unload(sb->s_encoding);
> + if (sb->s_encoding)
> + utf8_unload(sb->s_encoding);
> #endif
>
> #ifdef CONFIG_QUOTA
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 706979375..0a04983c2 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1430,7 +1430,8 @@ static void f2fs_put_super(struct super_block *sb)
> for (i = 0; i < NR_PAGE_TYPE; i++)
> kvfree(sbi->write_io[i]);
> #ifdef CONFIG_UNICODE
> - utf8_unload(sb->s_encoding);
> + if (sb->s_encoding)
> + utf8_unload(sb->s_encoding);
> #endif
> kfree(sbi);
> }
> @@ -4073,8 +4074,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> kvfree(sbi->write_io[i]);
>
> #ifdef CONFIG_UNICODE
> - utf8_unload(sb->s_encoding);
> - sb->s_encoding = NULL;
> + if (sb->s_encoding) {
> + utf8_unload(sb->s_encoding);
> + sb->s_encoding = NULL;
> + }
> #endif
> free_options:
> #ifdef CONFIG_QUOTA
--
Gabriel Krisman Bertazi
