Messages in this thread |  | | Date | Wed, 18 Apr 2018 12:42:51 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 1/2] hfs: fix potential refcnt problem of nls module |
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On Tue, 17 Apr 2018 15:05:32 +0800 Chengguang Xu <cgxu519@gmx.com> 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.
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