| Message ID | 1496424146-10928-1-git-send-email-housel@acm.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
On 06/02/2017 10:22 AM, Peter S. Housel wrote: > An earlier change to this function (3bdae810721b) fixed a leak in the > case of an unsuccessful call to brcmf_sdiod_buffrw(). However, the > glob_skb buffer, used for emulating a scattering read, is never used > or referenced after its contents are copied into the destination > buffers, and therefore always needs to be freed by the end of the > function. That looks correct, could you add the relevant Fixes tag for this? Fixes: 3bdae810721b ("brcmfmac: Fix glob_skb leak in brcmf_sdiod_recv_chain") Fixes: a413e39a38573 ("brcmfmac: fix brcmf_sdcard_recv_chain() for host without sg support") BTW, you made the same typo that I did, it's actually glom_skb ;) > > Signed-off-by: Peter S. Housel <housel@acm.org> > --- > drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c > index 9b970dc..4c5064f 100644 > --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c > +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c > @@ -727,15 +727,16 @@ int brcmf_sdiod_recv_chain(struct brcmf_sdio_dev *sdiodev, > return -ENOMEM; > err = brcmf_sdiod_buffrw(sdiodev, SDIO_FUNC_2, false, addr, > glom_skb); > - if (err) { > - brcmu_pkt_buf_free_skb(glom_skb); > - goto done; > - } > + if (err) > + goto free_glom_skb; > > skb_queue_walk(pktq, skb) { > memcpy(skb->data, glom_skb->data, skb->len); > skb_pull(glom_skb, skb->len); > } > + > +free_glom_skb: > + brcmu_pkt_buf_free_skb(glom_skb); > } else > err = brcmf_sdiod_sglist_rw(sdiodev, SDIO_FUNC_2, false, addr, > pktq); >
On Fri, Jun 2, 2017 at 10:22 AM, Peter S. Housel <housel@acm.org> wrote: > An earlier change to this function (3bdae810721b) fixed a leak in the > case of an unsuccessful call to brcmf_sdiod_buffrw(). However, the > glob_skb buffer, used for emulating a scattering read, is never used > or referenced after its contents are copied into the destination > buffers, and therefore always needs to be freed by the end of the > function. > > Signed-off-by: Peter S. Housel <housel@acm.org> > --- > drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c > index 9b970dc..4c5064f 100644 > --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c > +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c > @@ -727,15 +727,16 @@ int brcmf_sdiod_recv_chain(struct brcmf_sdio_dev *sdiodev, > return -ENOMEM; > err = brcmf_sdiod_buffrw(sdiodev, SDIO_FUNC_2, false, addr, > glom_skb); > - if (err) { > - brcmu_pkt_buf_free_skb(glom_skb); > - goto done; > - } > + if (err) > + goto free_glom_skb; > > skb_queue_walk(pktq, skb) { > memcpy(skb->data, glom_skb->data, skb->len); > skb_pull(glom_skb, skb->len); > } > + > +free_glom_skb: > + brcmu_pkt_buf_free_skb(glom_skb); What about if (!err) { skb_queue_walk(pktq, skb) { memcpy(skb->data, glom_skb->data, skb->len); skb_pull(glom_skb, skb->len); } } brcmu_pkt_buf_free_skb(glom_skb); Then no goto is needed. Thanks, Franky > } else > err = brcmf_sdiod_sglist_rw(sdiodev, SDIO_FUNC_2, false, addr, > pktq); > -- > 2.7.4 >
On Fri, Jun 2, 2017 at 9:52 PM, Franky Lin <franky.lin@broadcom.com> wrote: > On Fri, Jun 2, 2017 at 10:22 AM, Peter S. Housel <housel@acm.org> wrote: >> err = brcmf_sdiod_buffrw(sdiodev, SDIO_FUNC_2, false, addr, >> glom_skb); >> - if (err) { >> - brcmu_pkt_buf_free_skb(glom_skb); >> - goto done; >> - } > What about > if (!err) { > skb_queue_walk(pktq, skb) { > memcpy(skb->data, glom_skb->data, skb->len); > skb_pull(glom_skb, skb->len); > } > } > brcmu_pkt_buf_free_skb(glom_skb); > > Then no goto is needed. For my point of view it has two subtle inconveniences: 1. Not so usual pattern in use if (!ret) 2. Less error prone in case someone decides to expand the code and missed ! or something else there. Since both makes an approach less error prone I wouldn't suggest doing that as I commented in new version.
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c index 9b970dc..4c5064f 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c @@ -727,15 +727,16 @@ int brcmf_sdiod_recv_chain(struct brcmf_sdio_dev *sdiodev, return -ENOMEM; err = brcmf_sdiod_buffrw(sdiodev, SDIO_FUNC_2, false, addr, glom_skb); - if (err) { - brcmu_pkt_buf_free_skb(glom_skb); - goto done; - } + if (err) + goto free_glom_skb; skb_queue_walk(pktq, skb) { memcpy(skb->data, glom_skb->data, skb->len); skb_pull(glom_skb, skb->len); } + +free_glom_skb: + brcmu_pkt_buf_free_skb(glom_skb); } else err = brcmf_sdiod_sglist_rw(sdiodev, SDIO_FUNC_2, false, addr, pktq);
An earlier change to this function (3bdae810721b) fixed a leak in the case of an unsuccessful call to brcmf_sdiod_buffrw(). However, the glob_skb buffer, used for emulating a scattering read, is never used or referenced after its contents are copied into the destination buffers, and therefore always needs to be freed by the end of the function. Signed-off-by: Peter S. Housel <housel@acm.org> --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)