RE: [PATCH v2] wifi: rtw89: debug: Fix memory leak in __print_txpwr_map()

[Ping-Ke Shih]

Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx> wrote:
> Zilin Guan <zilin@xxxxxxxxxx> wrote:
> >
> > In __print_txpwr_map(), memory is allocated to bufp via vzalloc().
> > If max_valid_addr is 0, the function returns -EOPNOTSUPP immediately
> > without freeing bufp, leading to a memory leak.
> >
> > Since the validation of max_valid_addr does not depend on the allocated
> > memory, fix this by moving the vzalloc() call after the check.
> >
> > Compile tested only. Issue found using a prototype static analysis tool
> > and code review.
> >
> > Fixes: 036042e15770 ("wifi: rtw89: debug: txpwr table supports Wi-Fi 7 chips")
> > Suggested-by: Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx>
> > Signed-off-by: Zilin Guan <zilin@xxxxxxxxxx>
> > ---
> > Changes in v2:
> > - Move memory allocation after validation check to avoid leak.
> >
> >  drivers/net/wireless/realtek/rtw89/debug.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/net/wireless/realtek/rtw89/debug.c
> > b/drivers/net/wireless/realtek/rtw89/debug.c
> > index 1264c2f82600..987eef8170f2 100644
> > --- a/drivers/net/wireless/realtek/rtw89/debug.c
> > +++ b/drivers/net/wireless/realtek/rtw89/debug.c
> > @@ -825,10 +825,6 @@ static ssize_t __print_txpwr_map(struct rtw89_dev *rtwdev, char
> > *buf, size_t buf
> >         s8 *bufp, tmp;
> >         int ret;
> >
> > -       bufp = vzalloc(map->addr_to - map->addr_from + 4);
> > -       if (!bufp)
> > -               return -ENOMEM;
> > -
> >         if (path_num == 1)
> >                 max_valid_addr = map->addr_to_1ss;
> >         else
> > @@ -837,6 +833,10 @@ static ssize_t __print_txpwr_map(struct rtw89_dev *rtwdev, char
> > *buf, size_t buf
> >         if (max_valid_addr == 0)
> >                 return -EOPNOTSUPP;
> >
> > +       bufp = vzalloc(map->addr_to - map->addr_from + 4);
> > +       if (!bufp)
> > +               return -ENOMEM;
> > +
> >         for (addr = map->addr_from; addr <= max_valid_addr; addr += 4) {
> >                 ret = rtw89_mac_txpwr_read32(rtwdev, RTW89_PHY_0, addr, &val);
> >                 if (ret)
> > --
> > 2.34.1
> 
> Looks good to me.

I suppose I can add 
Reviewed-by: Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx>

Okay?