From 57bbe088e3c98d05f1341adaf480c6d91a574a4e Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Tue, 10 Aug 2021 13:10:44 -0300 Subject: [PATCH 1/2] cifs: fix signed integer overflow when fl_end is OFFSET_MAX 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) Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 5 +++++ fs/cifs/cifssmb.c | 3 ++- fs/cifs/file.c | 8 ++++---- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index c0bfc2f01030..f7bdf865f439 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1964,4 +1964,9 @@ static inline bool is_tcon_dfs(struct cifs_tcon *tcon) tcon->share_flags & (SHI1005_FLAGS_DFS | SHI1005_FLAGS_DFS_ROOT); } +static inline u64 cifs_flock_len(struct file_lock *fl) +{ + return fl->fl_end == OFFSET_MAX ? fl->fl_end - fl->fl_start: fl->fl_end - fl->fl_start + 1; +} + #endif /* _CIFS_GLOB_H */ diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 65d1a65bfc37..6ab6cf669438 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -2607,7 +2607,8 @@ CIFSSMBPosixLock(const unsigned int xid, struct cifs_tcon *tcon, 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); } } diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 0a72840a88f1..e1cfd50996a0 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1385,7 +1385,7 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile) 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 @@ -1501,7 +1501,7 @@ cifs_getlk(struct file *file, struct file_lock *flock, __u32 type, 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; @@ -1599,7 +1599,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 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); @@ -1703,7 +1703,7 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type, 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; -- 2.30.2