| Message ID | 20241120142732.55210-1-mszeredi@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | statmount: clean up unescaped option handling | expand |
On Wed, 2024-11-20 at 15:27 +0100, Miklos Szeredi wrote: > Move common code from opt_array/opt_sec_array to helper. This helper > does more than just unescape options, so rename to > statmount_opt_process(). > > Handle corner case of just a single character in options. > > Rename some local variables to better describe their function. > > Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> > --- > fs/namespace.c | 44 +++++++++++++++++++------------------------- > 1 file changed, 19 insertions(+), 25 deletions(-) > > diff --git a/fs/namespace.c b/fs/namespace.c > index eb34a5160f64..23e81c2a1e3f 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -5057,21 +5057,32 @@ static int statmount_mnt_opts(struct kstatmount *s, struct seq_file *seq) > return 0; > } > > -static inline int statmount_opt_unescape(struct seq_file *seq, char *buf_start) > +static inline int statmount_opt_process(struct seq_file *seq, size_t start) > { > - char *buf_end, *opt_start, *opt_end; > + char *buf_end, *opt_end, *src, *dst; > int count = 0; > > + if (unlikely(seq_has_overflowed(seq))) > + return -EAGAIN; > + > buf_end = seq->buf + seq->count; > + dst = seq->buf + start; > + src = dst + 1; /* skip initial comma */ > + > + if (src >= buf_end) { > + seq->count = start; > + return 0; > + } > + > *buf_end = '\0'; > - for (opt_start = buf_start + 1; opt_start < buf_end; opt_start = opt_end + 1) { > - opt_end = strchrnul(opt_start, ','); > + for (; src < buf_end; src = opt_end + 1) { > + opt_end = strchrnul(src, ','); > *opt_end = '\0'; > - buf_start += string_unescape(opt_start, buf_start, 0, UNESCAPE_OCTAL) + 1; > + dst += string_unescape(src, dst, 0, UNESCAPE_OCTAL) + 1; > if (WARN_ON_ONCE(++count == INT_MAX)) > return -EOVERFLOW; > } > - seq->count = buf_start - 1 - seq->buf; > + seq->count = dst - 1 - seq->buf; > return count; > } > > @@ -5080,24 +5091,16 @@ static int statmount_opt_array(struct kstatmount *s, struct seq_file *seq) > struct vfsmount *mnt = s->mnt; > struct super_block *sb = mnt->mnt_sb; > size_t start = seq->count; > - char *buf_start; > int err; > > if (!sb->s_op->show_options) > return 0; > > - buf_start = seq->buf + start; > err = sb->s_op->show_options(seq, mnt->mnt_root); > if (err) > return err; > > - if (unlikely(seq_has_overflowed(seq))) > - return -EAGAIN; > - > - if (seq->count == start) > - return 0; > - > - err = statmount_opt_unescape(seq, buf_start); > + err = statmount_opt_process(seq, start); > if (err < 0) > return err; > > @@ -5110,22 +5113,13 @@ static int statmount_opt_sec_array(struct kstatmount *s, struct seq_file *seq) > struct vfsmount *mnt = s->mnt; > struct super_block *sb = mnt->mnt_sb; > size_t start = seq->count; > - char *buf_start; > int err; > > - buf_start = seq->buf + start; > - > err = security_sb_show_options(seq, sb); > if (err) > return err; > > - if (unlikely(seq_has_overflowed(seq))) > - return -EAGAIN; > - > - if (seq->count == start) > - return 0; > - > - err = statmount_opt_unescape(seq, buf_start); > + err = statmount_opt_process(seq, start); > if (err < 0) > return err; > Reviewed-by: Jeff Layton <jlayton@kernel.org>
On Wed, 20 Nov 2024 15:27:23 +0100, Miklos Szeredi wrote: > Move common code from opt_array/opt_sec_array to helper. This helper > does more than just unescape options, so rename to > statmount_opt_process(). > > Handle corner case of just a single character in options. > > Rename some local variables to better describe their function. > > [...] Applied to the vfs.fixes branch of the vfs/vfs.git tree. Patches in the vfs.fixes branch should appear in linux-next soon. Please report any outstanding bugs that were missed during review in a new review to the original patch series allowing us to drop it. It's encouraged to provide Acked-bys and Reviewed-bys even though the patch has now been applied. If possible patch trailers will be updated. Note that commit hashes shown below are subject to change due to rebase, trailer updates or similar. If in doubt, please check the listed branch. tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git branch: vfs.fixes [1/1] statmount: clean up unescaped option handling https://git.kernel.org/vfs/vfs/c/d09ddc9b1976
diff --git a/fs/namespace.c b/fs/namespace.c index eb34a5160f64..23e81c2a1e3f 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -5057,21 +5057,32 @@ static int statmount_mnt_opts(struct kstatmount *s, struct seq_file *seq) return 0; } -static inline int statmount_opt_unescape(struct seq_file *seq, char *buf_start) +static inline int statmount_opt_process(struct seq_file *seq, size_t start) { - char *buf_end, *opt_start, *opt_end; + char *buf_end, *opt_end, *src, *dst; int count = 0; + if (unlikely(seq_has_overflowed(seq))) + return -EAGAIN; + buf_end = seq->buf + seq->count; + dst = seq->buf + start; + src = dst + 1; /* skip initial comma */ + + if (src >= buf_end) { + seq->count = start; + return 0; + } + *buf_end = '\0'; - for (opt_start = buf_start + 1; opt_start < buf_end; opt_start = opt_end + 1) { - opt_end = strchrnul(opt_start, ','); + for (; src < buf_end; src = opt_end + 1) { + opt_end = strchrnul(src, ','); *opt_end = '\0'; - buf_start += string_unescape(opt_start, buf_start, 0, UNESCAPE_OCTAL) + 1; + dst += string_unescape(src, dst, 0, UNESCAPE_OCTAL) + 1; if (WARN_ON_ONCE(++count == INT_MAX)) return -EOVERFLOW; } - seq->count = buf_start - 1 - seq->buf; + seq->count = dst - 1 - seq->buf; return count; } @@ -5080,24 +5091,16 @@ static int statmount_opt_array(struct kstatmount *s, struct seq_file *seq) struct vfsmount *mnt = s->mnt; struct super_block *sb = mnt->mnt_sb; size_t start = seq->count; - char *buf_start; int err; if (!sb->s_op->show_options) return 0; - buf_start = seq->buf + start; err = sb->s_op->show_options(seq, mnt->mnt_root); if (err) return err; - if (unlikely(seq_has_overflowed(seq))) - return -EAGAIN; - - if (seq->count == start) - return 0; - - err = statmount_opt_unescape(seq, buf_start); + err = statmount_opt_process(seq, start); if (err < 0) return err; @@ -5110,22 +5113,13 @@ static int statmount_opt_sec_array(struct kstatmount *s, struct seq_file *seq) struct vfsmount *mnt = s->mnt; struct super_block *sb = mnt->mnt_sb; size_t start = seq->count; - char *buf_start; int err; - buf_start = seq->buf + start; - err = security_sb_show_options(seq, sb); if (err) return err; - if (unlikely(seq_has_overflowed(seq))) - return -EAGAIN; - - if (seq->count == start) - return 0; - - err = statmount_opt_unescape(seq, buf_start); + err = statmount_opt_process(seq, start); if (err < 0) return err;
Move common code from opt_array/opt_sec_array to helper. This helper does more than just unescape options, so rename to statmount_opt_process(). Handle corner case of just a single character in options. Rename some local variables to better describe their function. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> --- fs/namespace.c | 44 +++++++++++++++++++------------------------- 1 file changed, 19 insertions(+), 25 deletions(-)