cifs: fix page reference leak with readv/writev
CIFS can leak pages reference gotten through GUP (get_user_pages*()
through iov_iter_get_pages()). This happen if cifs_send_async_read()
or cifs_write_from_iter() calls fail from within __cifs_readv() and
__cifs_writev() respectively. This patch move page unreference to
cifs_aio_ctx_release() which will happens on all code paths this is
all simpler to follow for correctness.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 9c0ccc0..7037a13 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2877,7 +2877,6 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx)
struct cifs_tcon *tcon;
struct cifs_sb_info *cifs_sb;
struct dentry *dentry = ctx->cfile->dentry;
- unsigned int i;
int rc;
tcon = tlink_tcon(ctx->cfile->tlink);
@@ -2941,10 +2940,6 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx)
kref_put(&wdata->refcount, cifs_uncached_writedata_release);
}
- if (!ctx->direct_io)
- for (i = 0; i < ctx->npages; i++)
- put_page(ctx->bv[i].bv_page);
-
cifs_stats_bytes_written(tcon, ctx->total_len);
set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags);
@@ -3582,7 +3577,6 @@ collect_uncached_read_data(struct cifs_aio_ctx *ctx)
struct iov_iter *to = &ctx->iter;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *tcon;
- unsigned int i;
int rc;
tcon = tlink_tcon(ctx->cfile->tlink);
@@ -3666,15 +3660,8 @@ collect_uncached_read_data(struct cifs_aio_ctx *ctx)
kref_put(&rdata->refcount, cifs_uncached_readdata_release);
}
- if (!ctx->direct_io) {
- for (i = 0; i < ctx->npages; i++) {
- if (ctx->should_dirty)
- set_page_dirty(ctx->bv[i].bv_page);
- put_page(ctx->bv[i].bv_page);
- }
-
+ if (!ctx->direct_io)
ctx->total_len = ctx->len - iov_iter_count(to);
- }
/* mask nodata case */
if (rc == -ENODATA)