From cb7a69e605908c34aad47644afeb26a765ade8d7 Mon Sep 17 00:00:00 2001 From: Deepa Dinamani Date: Fri, 22 Mar 2019 14:32:35 -0700 Subject: fs: cifs: Initialize filesystem timestamp ranges Fill in the appropriate limits to avoid inconsistencies in the vfs cached inode times when timestamps are outside the permitted range. Also fixed cnvrtDosUnixTm calculations to avoid int overflow while computing maximum date. References: http://cifs.com/ https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-cifs/d416ff7c-c536-406e-a951-4f04b2fd1d2b Signed-off-by: Deepa Dinamani Acked-by: Jeff Layton Cc: sfrench@samba.org Cc: linux-cifs@vger.kernel.org --- fs/cifs/cifsfs.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'fs/cifs/cifsfs.c') diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 3289b566463f..7a75726442ad 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -56,6 +56,15 @@ #include "dfs_cache.h" #endif +/* + * DOS dates from 1980/1/1 through 2107/12/31 + * Protocol specifications indicate the range should be to 119, which + * limits maximum year to 2099. But this range has not been checked. + */ +#define SMB_DATE_MAX (127<<9 | 12<<5 | 31) +#define SMB_DATE_MIN (0<<9 | 1<<5 | 1) +#define SMB_TIME_MAX (23<<11 | 59<<5 | 29) + int cifsFYI = 0; bool traceSMB; bool enable_oplocks = true; @@ -142,6 +151,7 @@ cifs_read_super(struct super_block *sb) struct inode *inode; struct cifs_sb_info *cifs_sb; struct cifs_tcon *tcon; + struct timespec64 ts; int rc = 0; cifs_sb = CIFS_SB(sb); @@ -161,6 +171,18 @@ cifs_read_super(struct super_block *sb) /* BB FIXME fix time_gran to be larger for LANMAN sessions */ sb->s_time_gran = 100; + if (tcon->unix_ext) { + ts = cifs_NTtimeToUnix(0); + sb->s_time_min = ts.tv_sec; + ts = cifs_NTtimeToUnix(cpu_to_le64(S64_MAX)); + sb->s_time_max = ts.tv_sec; + } else { + ts = cnvrtDosUnixTm(cpu_to_le16(SMB_DATE_MIN), 0, 0); + sb->s_time_min = ts.tv_sec; + ts = cnvrtDosUnixTm(cpu_to_le16(SMB_DATE_MAX), cpu_to_le16(SMB_TIME_MAX), 0); + sb->s_time_max = ts.tv_sec; + } + sb->s_magic = CIFS_MAGIC_NUMBER; sb->s_op = &cifs_super_ops; sb->s_xattr = cifs_xattr_handlers; -- cgit v1.2.3