[PATCH 4.4 054/115] afs: Prevent callback expiry timer overflow

Greg Kroah-Hartman
2017-12-18T17:56:48Z

From: Tina Ruchandani <ruchandani.tina@gmail.com>

[ Upstream commit 56e714312e7dbd6bb83b2f78d3ec19a404c7649f ]

get_seconds() returns real wall-clock seconds. On 32-bit systems
this value will overflow in year 2038 and beyond. This patch changes
afs_vnode record to use ktime_get_real_seconds() instead, for the
fields cb_expires and cb_expires_at.

Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/afs/fsclient.c | 2 +-
fs/afs/inode.c | 7 ++++---
fs/afs/internal.h | 4 ++--
3 files changed, 7 insertions(+), 6 deletions(-)

--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -139,7 +139,7 @@ static void xdr_decode_AFSCallBack(const
vnode->cb_version = ntohl(*bp++);
vnode->cb_expiry = ntohl(*bp++);
vnode->cb_type = ntohl(*bp++);
- vnode->cb_expires = vnode->cb_expiry + get_seconds();
+ vnode->cb_expires = vnode->cb_expiry + ktime_get_real_seconds();
*_bp = bp;
}

--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -244,12 +244,13 @@ struct inode *afs_iget(struct super_bloc
vnode->cb_version = 0;
vnode->cb_expiry = 0;
vnode->cb_type = 0;
- vnode->cb_expires = get_seconds();
+ vnode->cb_expires = ktime_get_real_seconds();
} else {
vnode->cb_version = cb->version;
vnode->cb_expiry = cb->expiry;
vnode->cb_type = cb->type;
- vnode->cb_expires = vnode->cb_expiry + get_seconds();
+ vnode->cb_expires = vnode->cb_expiry +
+ ktime_get_real_seconds();
}
}

@@ -322,7 +323,7 @@ int afs_validate(struct afs_vnode *vnode
!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
!test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
!test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
- if (vnode->cb_expires < get_seconds() + 10) {
+ if (vnode->cb_expires < ktime_get_real_seconds() + 10) {
_debug("callback expired");
set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
} else {
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -375,8 +375,8 @@ struct afs_vnode {
struct rb_node server_rb; /* link in server->fs_vnodes */
struct rb_node cb_promise; /* link in server->cb_promises */
struct work_struct cb_broken_work; /* work to be done on callback break */
- time_t cb_expires; /* time at which callback expires */
- time_t cb_expires_at; /* time used to order cb_promise */
+ time64_t cb_expires; /* time at which callback expires */
+ time64_t cb_expires_at; /* time used to order cb_promise */
unsigned cb_version; /* callback version */
unsigned cb_expiry; /* callback expiry time */
afs_callback_type_t cb_type; /* type of callback */