Re: [Qemu-devel] [PATCH 2/3] hw/9pfs/virtio-9p-local.c: use snprintf() instead of sprintf()

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

Chen Gang <gang.chen.5i5j@gmail.com> writes:

> On 03/03/2014 04:34 PM, Markus Armbruster wrote:
>> Chen Gang <gang.chen.5i5j@gmail.com> writes:
>> 
>>> 'ctx->fs_root' + 'path'/'fullname.data' may be larger than PATH_MAX, so
>>> need use snprintf() instead of sprintf() just like another area have done in 9pfs.
>>>
>>> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
>>> ---
>>>  hw/9pfs/virtio-9p-local.c | 7 ++++---
>>>  1 file changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
>>> index 77a04cd..61be75a 100644
>>> --- a/hw/9pfs/virtio-9p-local.c
>>> +++ b/hw/9pfs/virtio-9p-local.c
>>> @@ -898,7 +898,8 @@ static int local_remove(FsContext *ctx, const char *path)
>>>           * directory
>>>           */
>>>          if (S_ISDIR(stbuf.st_mode)) {
>>> -            sprintf(buffer, "%s/%s/%s", ctx->fs_root, path, VIRTFS_META_DIR);
>>> +            snprintf(buffer, ARRAY_SIZE(buffer), "%s/%s/%s",
>>> +                     ctx->fs_root, path, VIRTFS_META_DIR);
>>>              err = remove(buffer);
>>>              if (err < 0 && errno != ENOENT) {
>>>                  /*
>>> @@ -1033,8 +1034,8 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
>>>               * If directory remove .virtfs_metadata contained in the
>>>               * directory
>>>               */
>>> -            sprintf(buffer, "%s/%s/%s", ctx->fs_root,
>>> -                    fullname.data, VIRTFS_META_DIR);
>>> +            snprintf(buffer, ARRAY_SIZE(buffer), "%s/%s/%s", ctx->fs_root,
>>> +                     fullname.data, VIRTFS_META_DIR);
>>>              ret = remove(buffer);
>>>              if (ret < 0 && errno != ENOENT) {
>>>                  /*
>> 
>> Turns a buffer overrun bug into a truncation bug.  The next commit fixes
>> truncation bugs including this one.  Would be nice to spell this out in
>> the commit message.  Perhaps Aneesh can do it on commit.
>> 
>
> Please help doing it on commit.

Will update when i am applyting this to my tree.

-aneesh