diff options
| author | Dong Jia Shi | 2018-05-23 04:56:44 +0200 |
|---|---|---|
| committer | Cornelia Huck | 2018-05-29 09:27:42 +0200 |
| commit | 6238f92132a6da64b731de1a728fa46ffaa21f62 (patch) | |
| tree | 45465435d773ecf4a24a3f8ad240745da880b6ce | |
| parent | 5c1cfb1c3948fe93a32dfcd75223dda0f1558bb7 (diff) | |
vfio: ccw: set ccw->cda to NULL defensively
Let's avoid free on ccw->cda that points to a guest address
or an already freed memory area by setting it to NULL if memory
allocation didn't happen or failed.
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Message-Id: <20180523025645.8978-4-bjsdjshi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.c | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index b0f20230fc72..dbe7c7ac9ac8 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -502,7 +502,7 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, struct ccw1 *ccw; struct pfn_array_table *pat; unsigned long *idaws; - int idaw_nr; + int ret; ccw = chain->ch_ccw + idx; @@ -522,18 +522,19 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, * needed when translating a direct ccw to a idal ccw. */ pat = chain->ch_pat + idx; - if (pfn_array_table_init(pat, 1)) - return -ENOMEM; - idaw_nr = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, - ccw->cda, ccw->count); - if (idaw_nr < 0) - return idaw_nr; + ret = pfn_array_table_init(pat, 1); + if (ret) + goto out_init; + + ret = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, ccw->cda, ccw->count); + if (ret < 0) + goto out_init; /* Translate this direct ccw to a idal ccw. */ - idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL); + idaws = kcalloc(ret, sizeof(*idaws), GFP_DMA | GFP_KERNEL); if (!idaws) { - pfn_array_table_unpin_free(pat, cp->mdev); - return -ENOMEM; + ret = -ENOMEM; + goto out_unpin; } ccw->cda = (__u32) virt_to_phys(idaws); ccw->flags |= CCW_FLAG_IDA; @@ -541,6 +542,12 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, pfn_array_table_idal_create_words(pat, idaws); return 0; + +out_unpin: + pfn_array_table_unpin_free(pat, cp->mdev); +out_init: + ccw->cda = 0; + return ret; } static int ccwchain_fetch_idal(struct ccwchain *chain, @@ -570,7 +577,7 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, pat = chain->ch_pat + idx; ret = pfn_array_table_init(pat, idaw_nr); if (ret) - return ret; + goto out_init; /* Translate idal ccw to use new allocated idaws. */ idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL); @@ -602,6 +609,8 @@ out_free_idaws: kfree(idaws); out_unpin: pfn_array_table_unpin_free(pat, cp->mdev); +out_init: + ccw->cda = 0; return ret; } |