refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
fs/nfs/pnfs.c | 12 ++++++------
fs/nfs/pnfs.h | 4 ++--
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 3bcd669..499bb71 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -450,7 +450,7 @@ pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
{
INIT_LIST_HEAD(&lseg->pls_list);
INIT_LIST_HEAD(&lseg->pls_lc_list);
- atomic_set(&lseg->pls_refcount, 1);
+ refcount_set(&lseg->pls_refcount, 1);
set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
lseg->pls_layout = lo;
lseg->pls_range = *range;
@@ -507,13 +507,13 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
return;
dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
- atomic_read(&lseg->pls_refcount),
+ refcount_read(&lseg->pls_refcount),
test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
lo = lseg->pls_layout;
inode = lo->plh_inode;
- if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
+ if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
spin_unlock(&inode->i_lock);
return;
@@ -551,7 +551,7 @@ pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
struct list_head *tmp_list)
{
- if (!atomic_dec_and_test(&lseg->pls_refcount))
+ if (!refcount_dec_and_test(&lseg->pls_refcount))
return false;
pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
list_add(&lseg->pls_list, tmp_list);
@@ -570,7 +570,7 @@ static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
* outstanding io is finished.
*/
dprintk("%s: lseg %p ref %d\n", __func__, lseg,
- atomic_read(&lseg->pls_refcount));
+ refcount_read(&lseg->pls_refcount));
if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
rv = 1;
}
@@ -1546,7 +1546,7 @@ pnfs_find_lseg(struct pnfs_layout_hdr *lo,
}
dprintk("%s:Return lseg %p ref %d\n",
- __func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
+ __func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
return ret;
}
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index cefa7da..f0e98e1 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -64,7 +64,7 @@ struct pnfs_layout_segment {
struct list_head pls_list;
struct list_head pls_lc_list;
struct pnfs_layout_range pls_range;
- atomic_t pls_refcount;
+ refcount_t pls_refcount;
u32 pls_seq;
unsigned long pls_flags;
struct pnfs_layout_hdr *pls_layout;
@@ -394,7 +394,7 @@ static inline struct pnfs_layout_segment *
pnfs_get_lseg(struct pnfs_layout_segment *lseg)
{
if (lseg) {
- atomic_inc(&lseg->pls_refcount);
+ refcount_inc(&lseg->pls_refcount);
smp_mb__after_atomic();
}
return lseg;
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
