From: Paulo Alcantara <pc@cjr.nz>
Date: Thu, 19 May 2022 12:18:37 -0300
Subject: [PATCH] cifs: fix signed integer overflow when fl_end is OFFSET_MAX
Git-commit: d80c69846ddfddf437167b31ab4cd0de12f61001
References: bsc#1190317
Patch-mainline: v5.18
This fixes the following when running xfstests generic/504:
[ 134.394698] CIFS: Attempting to mount \\win16.vm.test\Share
[ 134.420905] CIFS: VFS: generate_smb3signingkey: dumping generated
AES session keys
[ 134.420911] CIFS: VFS: Session Id 05 00 00 00 00 c4 00 00
[ 134.420914] CIFS: VFS: Cipher type 1
[ 134.420917] CIFS: VFS: Session Key ea 0b d9 22 2e af 01 69 30 1b
15 74 bf 87 41 11
[ 134.420920] CIFS: VFS: Signing Key 59 28 43 5c f0 b6 b1 6f f5 7b
65 f2 9f 9e 58 7d
[ 134.420923] CIFS: VFS: ServerIn Key eb aa 58 c8 95 01 9a f7 91 98
e4 fa bc d8 74 f1
[ 134.420926] CIFS: VFS: ServerOut Key 08 5b 21 e5 2e 4e 86 f6 05 c2
58 e0 af 53 83 e7
[ 134.771946]
================================================================================
[ 134.771953] UBSAN: signed-integer-overflow in fs/cifs/file.c:1706:19
[ 134.771957] 9223372036854775807 + 1 cannot be represented in type
'long long int'
[ 134.771960] CPU: 4 PID: 2773 Comm: flock Not tainted 5.11.22 #1
[ 134.771964] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 134.771966] Call Trace:
[ 134.771970] dump_stack+0x8d/0xb5
[ 134.771981] ubsan_epilogue+0x5/0x50
[ 134.771988] handle_overflow+0xa3/0xb0
[ 134.771997] ? lockdep_hardirqs_on_prepare+0xe8/0x1b0
[ 134.772006] cifs_setlk+0x63c/0x680 [cifs]
[ 134.772085] ? _get_xid+0x5f/0xa0 [cifs]
[ 134.772085] cifs_flock+0x131/0x400 [cifs]
[ 134.772085] __x64_sys_flock+0xfc/0x120
[ 134.772085] do_syscall_64+0x33/0x40
[ 134.772085] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 134.772085] RIP: 0033:0x7fea4f83b3fb
[ 134.772085] Code: ff 48 8b 15 8f 1a 0d 00 f7 d8 64 89 02 b8 ff ff
ff ff eb da e8 16 0b 02 00 66 0f 1f 44 00 00 f3 0f 1e fa b8 49 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 5d 1a 0d 00 f7 d8 64 89
01 48
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
fs/cifs/cifsglob.h | 5 +++++
fs/cifs/cifssmb.c | 3 ++-
fs/cifs/file.c | 8 ++++----
3 files changed, 11 insertions(+), 5 deletions(-)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -2014,4 +2014,9 @@ static inline bool cifs_is_referral_serv
return is_tcon_dfs(tcon) || (ref && (ref->flags & DFSREF_REFERRAL_SERVER));
}
+static inline u64 cifs_flock_len(struct file_lock *fl)
+{
+ return fl->fl_end == OFFSET_MAX ? 0 : fl->fl_end - fl->fl_start + 1;
+}
+
#endif /* _CIFS_GLOB_H */
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2619,7 +2619,8 @@ CIFSSMBPosixLock(const unsigned int xid,
pLockData->fl_start = le64_to_cpu(parm_data->start);
pLockData->fl_end = pLockData->fl_start +
- le64_to_cpu(parm_data->length) - 1;
+ (le64_to_cpu(parm_data->length) ?
+ le64_to_cpu(parm_data->length) - 1 : 0);
pLockData->fl_pid = le32_to_cpu(parm_data->pid);
}
}
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1325,7 +1325,7 @@ cifs_push_posix_locks(struct cifsFileInf
cifs_dbg(VFS, "Can't push all brlocks!\n");
break;
}
- length = 1 + flock->fl_end - flock->fl_start;
+ length = cifs_flock_len(flock);
if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
type = CIFS_RDLCK;
else
@@ -1441,7 +1441,7 @@ cifs_getlk(struct file *file, struct fil
bool wait_flag, bool posix_lck, unsigned int xid)
{
int rc = 0;
- __u64 length = 1 + flock->fl_end - flock->fl_start;
+ __u64 length = cifs_flock_len(flock);
struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct TCP_Server_Info *server = tcon->ses->server;
@@ -1539,7 +1539,7 @@ cifs_unlock_range(struct cifsFileInfo *c
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
struct cifsLockInfo *li, *tmp;
- __u64 length = 1 + flock->fl_end - flock->fl_start;
+ __u64 length = cifs_flock_len(flock);
struct list_head tmp_llist;
INIT_LIST_HEAD(&tmp_llist);
@@ -1643,7 +1643,7 @@ cifs_setlk(struct file *file, struct fil
unsigned int xid)
{
int rc = 0;
- __u64 length = 1 + flock->fl_end - flock->fl_start;
+ __u64 length = cifs_flock_len(flock);
struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct TCP_Server_Info *server = tcon->ses->server;