| Message ID | 20221206030805.15934-1-jiasheng@iscas.ac.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] ice: Add check for kzalloc | expand |
Tue, Dec 06, 2022 at 04:08:05AM CET, jiasheng@iscas.ac.cn wrote: >As kzalloc may fail and return NULL pointer, >it should be better to check the return value >in order to avoid the NULL pointer dereference. Okay, so? Be imperative to the code base, tell it what to do in your patch description. > >Fixes: d6b98c8d242a ("ice: add write functionality for GNSS TTY") >Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> >--- > drivers/net/ethernet/intel/ice/ice_gnss.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > >diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c >index b5a7f246d230..6d3d5e75726b 100644 >--- a/drivers/net/ethernet/intel/ice/ice_gnss.c >+++ b/drivers/net/ethernet/intel/ice/ice_gnss.c >@@ -421,7 +421,7 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf) > const int ICE_TTYDRV_NAME_MAX = 14; > struct tty_driver *tty_driver; > char *ttydrv_name; >- unsigned int i; >+ unsigned int i, j; > int err; > > tty_driver = tty_alloc_driver(ICE_GNSS_TTY_MINOR_DEVICES, >@@ -462,6 +462,17 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf) > GFP_KERNEL); > pf->gnss_serial[i] = NULL; > >+ if (!pf->gnss_tty_port[i]) { >+ for (j = 0; j < i; j++) { >+ tty_port_destroy(pf->gnss_tty_port[j]); You are destroying port which you didn't call (pf->gnss_tty_port[i]) for. Also, you are introducing a code duplication here with the error path couple of lines below. Please convert this to goto-label error path so the cleanup code is shared. >+ kfree(pf->gnss_tty_port[j]); >+ } >+ kfree(ttydrv_name); >+ tty_driver_kref_put(pf->ice_gnss_tty_driver); >+ >+ return NULL; >+ } >+ > tty_port_init(pf->gnss_tty_port[i]); > tty_port_link_device(pf->gnss_tty_port[i], tty_driver, i); > } >-- >2.25.1 >
On Tue, Dec 06, 2022 at 11:08:05AM +0800, Jiasheng Jiang wrote: > As kzalloc may fail and return NULL pointer, > it should be better to check the return value > in order to avoid the NULL pointer dereference. > > Fixes: d6b98c8d242a ("ice: add write functionality for GNSS TTY") > Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> > --- > drivers/net/ethernet/intel/ice/ice_gnss.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) The idea is correct, but please change an implementation to use goto and proper unwind for whole function. It will remove duplication in the code which handles tty_port destroys. Thanks > > diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c > index b5a7f246d230..6d3d5e75726b 100644 > --- a/drivers/net/ethernet/intel/ice/ice_gnss.c > +++ b/drivers/net/ethernet/intel/ice/ice_gnss.c > @@ -421,7 +421,7 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf) > const int ICE_TTYDRV_NAME_MAX = 14; > struct tty_driver *tty_driver; > char *ttydrv_name; > - unsigned int i; > + unsigned int i, j; > int err; > > tty_driver = tty_alloc_driver(ICE_GNSS_TTY_MINOR_DEVICES, > @@ -462,6 +462,17 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf) > GFP_KERNEL); > pf->gnss_serial[i] = NULL; > > + if (!pf->gnss_tty_port[i]) { > + for (j = 0; j < i; j++) { > + tty_port_destroy(pf->gnss_tty_port[j]); > + kfree(pf->gnss_tty_port[j]); > + } > + kfree(ttydrv_name); > + tty_driver_kref_put(pf->ice_gnss_tty_driver); > + > + return NULL; > + } > + > tty_port_init(pf->gnss_tty_port[i]); > tty_port_link_device(pf->gnss_tty_port[i], tty_driver, i); > } > -- > 2.25.1 >
diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c index b5a7f246d230..6d3d5e75726b 100644 --- a/drivers/net/ethernet/intel/ice/ice_gnss.c +++ b/drivers/net/ethernet/intel/ice/ice_gnss.c @@ -421,7 +421,7 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf) const int ICE_TTYDRV_NAME_MAX = 14; struct tty_driver *tty_driver; char *ttydrv_name; - unsigned int i; + unsigned int i, j; int err; tty_driver = tty_alloc_driver(ICE_GNSS_TTY_MINOR_DEVICES, @@ -462,6 +462,17 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf) GFP_KERNEL); pf->gnss_serial[i] = NULL; + if (!pf->gnss_tty_port[i]) { + for (j = 0; j < i; j++) { + tty_port_destroy(pf->gnss_tty_port[j]); + kfree(pf->gnss_tty_port[j]); + } + kfree(ttydrv_name); + tty_driver_kref_put(pf->ice_gnss_tty_driver); + + return NULL; + } + tty_port_init(pf->gnss_tty_port[i]); tty_port_link_device(pf->gnss_tty_port[i], tty_driver, i); }
As kzalloc may fail and return NULL pointer, it should be better to check the return value in order to avoid the NULL pointer dereference. Fixes: d6b98c8d242a ("ice: add write functionality for GNSS TTY") Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> --- drivers/net/ethernet/intel/ice/ice_gnss.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)