2018-04-17 07:07:46

by Chengguang Xu

[permalink] [raw]
Subject: [PATCH 1/2] hfs: fix potential refcnt problem of nls module

When specifying iocharset/codepage multiple times in a mount,
current option parsing will cause inaccurate refcount of nls
module. Hence, call unload_nls for previous one in this case.

Signed-off-by: Chengguang Xu <[email protected]>
---
fs/hfs/super.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 1738767..6a5f6fd 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -329,8 +329,10 @@ static int parse_options(char *options, struct hfs_sb_info *hsb)
return 0;
}
p = match_strdup(&args[0]);
- if (p)
+ if (p) {
+ unload_nls(hsb->nls_disk);
hsb->nls_disk = load_nls(p);
+ }
if (!hsb->nls_disk) {
pr_err("unable to load codepage \"%s\"\n", p);
kfree(p);
@@ -344,8 +346,10 @@ static int parse_options(char *options, struct hfs_sb_info *hsb)
return 0;
}
p = match_strdup(&args[0]);
- if (p)
+ if (p) {
+ unload_nls(hsb->nls_io);
hsb->nls_io = load_nls(p);
+ }
if (!hsb->nls_io) {
pr_err("unable to load iocharset \"%s\"\n", p);
kfree(p);
--
1.8.3.1



2018-04-17 07:07:46

by Chengguang Xu

[permalink] [raw]
Subject: [PATCH 2/2] hfsplus: fix potential refcnt problem of nls module

When specifying nls option multiple times in a mount,
current option parsing will cause inaccurate refcount of nls
module. Hence, call unload_nls for previous one in this case.

Signed-off-by: Chengguang Xu <[email protected]>
---
fs/hfsplus/options.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index 047e05c..068d4e2 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -171,8 +171,10 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
return 0;
}
p = match_strdup(&args[0]);
- if (p)
+ if (p) {
+ unload_nls(sbi->nls);
sbi->nls = load_nls(p);
+ }
if (!sbi->nls) {
pr_err("unable to load nls mapping \"%s\"\n",
p);
--
1.8.3.1


2018-04-18 17:12:25

by Viacheslav Dubeyko

[permalink] [raw]
Subject: Re: [PATCH 1/2] hfs: fix potential refcnt problem of nls module

On Tue, 2018-04-17 at 15:05 +0800, Chengguang Xu wrote:
> When specifying iocharset/codepage multiple times in a mount,
> current option parsing will cause inaccurate refcount of nls
> module. Hence, call unload_nls for previous one in this case.
>
> Signed-off-by: Chengguang Xu <[email protected]>


Looks good.

Reviewed-by: Vyacheslav Dubeyko <[email protected]>

Thanks,
Vyacheslav Dubeyko.


> ---
>  fs/hfs/super.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/fs/hfs/super.c b/fs/hfs/super.c
> index 1738767..6a5f6fd 100644
> --- a/fs/hfs/super.c
> +++ b/fs/hfs/super.c
> @@ -329,8 +329,10 @@ static int parse_options(char *options, struct
> hfs_sb_info *hsb)
>   return 0;
>   }
>   p = match_strdup(&args[0]);
> - if (p)
> + if (p) {
> + unload_nls(hsb->nls_disk);
>   hsb->nls_disk = load_nls(p);
> + }
>   if (!hsb->nls_disk) {
>   pr_err("unable to load codepage
> \"%s\"\n", p);
>   kfree(p);
> @@ -344,8 +346,10 @@ static int parse_options(char *options, struct
> hfs_sb_info *hsb)
>   return 0;
>   }
>   p = match_strdup(&args[0]);
> - if (p)
> + if (p) {
> + unload_nls(hsb->nls_io);
>   hsb->nls_io = load_nls(p);
> + }
>   if (!hsb->nls_io) {
>   pr_err("unable to load iocharset
> \"%s\"\n", p);
>   kfree(p);

2018-04-18 17:12:38

by Viacheslav Dubeyko

[permalink] [raw]
Subject: Re: [PATCH 2/2] hfsplus: fix potential refcnt problem of nls module

On Tue, 2018-04-17 at 15:05 +0800, Chengguang Xu wrote:
> When specifying nls option multiple times in a mount,
> current option parsing will cause inaccurate refcount of nls
> module. Hence, call unload_nls for previous one in this case.
>
> Signed-off-by: Chengguang Xu <[email protected]>


Looks good.

Reviewed-by: Vyacheslav Dubeyko <[email protected]>

Thanks,
Vyacheslav Dubeyko.


> ---
>  fs/hfsplus/options.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
> index 047e05c..068d4e2 100644
> --- a/fs/hfsplus/options.c
> +++ b/fs/hfsplus/options.c
> @@ -171,8 +171,10 @@ int hfsplus_parse_options(char *input, struct
> hfsplus_sb_info *sbi)
>   return 0;
>   }
>   p = match_strdup(&args[0]);
> - if (p)
> + if (p) {
> + unload_nls(sbi->nls);
>   sbi->nls = load_nls(p);
> + }
>   if (!sbi->nls) {
>   pr_err("unable to load nls mapping
> \"%s\"\n",
>          p);

2018-04-18 19:44:12

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 1/2] hfs: fix potential refcnt problem of nls module

On Tue, 17 Apr 2018 15:05:32 +0800 Chengguang Xu <[email protected]> wrote:

> When specifying iocharset/codepage multiple times in a mount,
> current option parsing will cause inaccurate refcount of nls
> module. Hence, call unload_nls for previous one in this case.
>
> ...
>
> --- a/fs/hfs/super.c
> +++ b/fs/hfs/super.c
> @@ -329,8 +329,10 @@ static int parse_options(char *options, struct hfs_sb_info *hsb)
> return 0;
> }
> p = match_strdup(&args[0]);
> - if (p)
> + if (p) {
> + unload_nls(hsb->nls_disk);
> hsb->nls_disk = load_nls(p);
> + }
> if (!hsb->nls_disk) {
> pr_err("unable to load codepage \"%s\"\n", p);
> kfree(p);
> @@ -344,8 +346,10 @@ static int parse_options(char *options, struct hfs_sb_info *hsb)
> return 0;
> }
> p = match_strdup(&args[0]);
> - if (p)
> + if (p) {
> + unload_nls(hsb->nls_io);
> hsb->nls_io = load_nls(p);
> + }
> if (!hsb->nls_io) {
> pr_err("unable to load iocharset \"%s\"\n", p);
> kfree(p);

Confused.

break;
: case opt_codepage:
: if (hsb->nls_disk) {
: pr_err("unable to change codepage\n");
: return 0;
: }

Here, hsb->nls_disk is known to be zero.

: p = match_strdup(&args[0]);
: if (p) {
: unload_nls(hsb->nls_disk);

So this will always do unload_nls(0).

: hsb->nls_disk = load_nls(p);
: }

And the same applies to your opt_iocharset change.

2018-04-18 19:46:17

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 2/2] hfsplus: fix potential refcnt problem of nls module

On Tue, 17 Apr 2018 15:05:33 +0800 Chengguang Xu <[email protected]> wrote:

> When specifying nls option multiple times in a mount,
> current option parsing will cause inaccurate refcount of nls
> module. Hence, call unload_nls for previous one in this case.
>
> --- a/fs/hfsplus/options.c
> +++ b/fs/hfsplus/options.c
> @@ -171,8 +171,10 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
> return 0;
> }
> p = match_strdup(&args[0]);
> - if (p)
> + if (p) {
> + unload_nls(sbi->nls);
> sbi->nls = load_nls(p);
> + }
> if (!sbi->nls) {
> pr_err("unable to load nls mapping \"%s\"\n",
> p);

Same problem as in [patch 1/2]

2018-04-19 01:20:28

by Chengguang Xu

[permalink] [raw]
Subject: Re: [PATCH 1/2] hfs: fix potential refcnt problem of nls module

?? 2018??4??19?գ?????3:42??Andrew Morton <[email protected]> д????
>
> On Tue, 17 Apr 2018 15:05:32 +0800 Chengguang Xu <[email protected]> wrote:
>
>> When specifying iocharset/codepage multiple times in a mount,
>> current option parsing will cause inaccurate refcount of nls
>> module. Hence, call unload_nls for previous one in this case.
>>
>> ...
>>
>> --- a/fs/hfs/super.c
>> +++ b/fs/hfs/super.c
>> @@ -329,8 +329,10 @@ static int parse_options(char *options, struct hfs_sb_info *hsb)
>> return 0;
>> }
>> p = match_strdup(&args[0]);
>> - if (p)
>> + if (p) {
>> + unload_nls(hsb->nls_disk);
>> hsb->nls_disk = load_nls(p);
>> + }
>> if (!hsb->nls_disk) {
>> pr_err("unable to load codepage \"%s\"\n", p);
>> kfree(p);
>> @@ -344,8 +346,10 @@ static int parse_options(char *options, struct hfs_sb_info *hsb)
>> return 0;
>> }
>> p = match_strdup(&args[0]);
>> - if (p)
>> + if (p) {
>> + unload_nls(hsb->nls_io);
>> hsb->nls_io = load_nls(p);
>> + }
>> if (!hsb->nls_io) {
>> pr_err("unable to load iocharset \"%s\"\n", p);
>> kfree(p);
>
> Confused.
>
> break;
> : case opt_codepage:
> : if (hsb->nls_disk) {
> : pr_err("unable to change codepage\n");
> : return 0;
> : }
>
> Here, hsb->nls_disk is known to be zero.
>
> : p = match_strdup(&args[0]);
> : if (p) {
> : unload_nls(hsb->nls_disk);
>
> So this will always do unload_nls(0).
>
> : hsb->nls_disk = load_nls(p);
> : }
>
> And the same applies to your opt_iocharset change.

You are right. Sorry I just misread this part, please just drop the patch.

Thanks.