* [brauner-vfs:vfs.all 11/48] fs/notify/fanotify/fanotify_user.c:2004:13: warning: variable 'obj' is used uninitialized whenever 'if' condition is false
@ 2025-02-05 16:16 kernel test robot
2025-02-05 16:20 ` Christian Brauner
0 siblings, 1 reply; 2+ messages in thread
From: kernel test robot @ 2025-02-05 16:16 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: llvm, oe-kbuild-all, Christian Brauner, Christian Brauner
tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git vfs.all
head: b7601b2abc4dbae86d85da3939ce185eac2ed4ff
commit: 21c1471c81dc7fd8de1f47d74cef9efc91356971 [11/48] fanotify: notify on mount attach and detach
config: i386-buildonly-randconfig-005-20250205 (https://download.01.org/0day-ci/archive/20250206/202502060049.cygRkOiu-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250206/202502060049.cygRkOiu-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502060049.cygRkOiu-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> fs/notify/fanotify/fanotify_user.c:2004:13: warning: variable 'obj' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
2004 | } else if (obj_type == FSNOTIFY_OBJ_TYPE_MNTNS) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/notify/fanotify/fanotify_user.c:2009:7: note: uninitialized use occurs here
2009 | if (!obj)
| ^~~
fs/notify/fanotify/fanotify_user.c:2004:9: note: remove the 'if' if its condition is always true
2004 | } else if (obj_type == FSNOTIFY_OBJ_TYPE_MNTNS) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/notify/fanotify/fanotify_user.c:1819:11: note: initialize the variable 'obj' to silence this warning
1819 | void *obj;
| ^
| = NULL
1 warning generated.
vim +2004 fs/notify/fanotify/fanotify_user.c
1806
1807 static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
1808 int dfd, const char __user *pathname)
1809 {
1810 struct inode *inode = NULL;
1811 struct fsnotify_group *group;
1812 struct path path;
1813 struct fan_fsid __fsid, *fsid = NULL;
1814 u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS;
1815 unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
1816 unsigned int mark_cmd = flags & FANOTIFY_MARK_CMD_BITS;
1817 unsigned int ignore = flags & FANOTIFY_MARK_IGNORE_BITS;
1818 unsigned int obj_type, fid_mode;
1819 void *obj;
1820 u32 umask = 0;
1821 int ret;
1822
1823 pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
1824 __func__, fanotify_fd, flags, dfd, pathname, mask);
1825
1826 /* we only use the lower 32 bits as of right now. */
1827 if (upper_32_bits(mask))
1828 return -EINVAL;
1829
1830 if (flags & ~FANOTIFY_MARK_FLAGS)
1831 return -EINVAL;
1832
1833 switch (mark_type) {
1834 case FAN_MARK_INODE:
1835 obj_type = FSNOTIFY_OBJ_TYPE_INODE;
1836 break;
1837 case FAN_MARK_MOUNT:
1838 obj_type = FSNOTIFY_OBJ_TYPE_VFSMOUNT;
1839 break;
1840 case FAN_MARK_FILESYSTEM:
1841 obj_type = FSNOTIFY_OBJ_TYPE_SB;
1842 break;
1843 case FAN_MARK_MNTNS:
1844 obj_type = FSNOTIFY_OBJ_TYPE_MNTNS;
1845 break;
1846 default:
1847 return -EINVAL;
1848 }
1849
1850 switch (mark_cmd) {
1851 case FAN_MARK_ADD:
1852 case FAN_MARK_REMOVE:
1853 if (!mask)
1854 return -EINVAL;
1855 break;
1856 case FAN_MARK_FLUSH:
1857 if (flags & ~(FANOTIFY_MARK_TYPE_BITS | FAN_MARK_FLUSH))
1858 return -EINVAL;
1859 break;
1860 default:
1861 return -EINVAL;
1862 }
1863
1864 if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS))
1865 valid_mask |= FANOTIFY_PERM_EVENTS;
1866
1867 if (mask & ~valid_mask)
1868 return -EINVAL;
1869
1870
1871 /* We don't allow FAN_MARK_IGNORE & FAN_MARK_IGNORED_MASK together */
1872 if (ignore == (FAN_MARK_IGNORE | FAN_MARK_IGNORED_MASK))
1873 return -EINVAL;
1874
1875 /*
1876 * Event flags (FAN_ONDIR, FAN_EVENT_ON_CHILD) have no effect with
1877 * FAN_MARK_IGNORED_MASK.
1878 */
1879 if (ignore == FAN_MARK_IGNORED_MASK) {
1880 mask &= ~FANOTIFY_EVENT_FLAGS;
1881 umask = FANOTIFY_EVENT_FLAGS;
1882 }
1883
1884 CLASS(fd, f)(fanotify_fd);
1885 if (fd_empty(f))
1886 return -EBADF;
1887
1888 /* verify that this is indeed an fanotify instance */
1889 if (unlikely(fd_file(f)->f_op != &fanotify_fops))
1890 return -EINVAL;
1891 group = fd_file(f)->private_data;
1892
1893 /* Only report mount events on mnt namespace */
1894 if (FAN_GROUP_FLAG(group, FAN_REPORT_MNT)) {
1895 if (mask & ~FANOTIFY_MOUNT_EVENTS)
1896 return -EINVAL;
1897 if (mark_type != FAN_MARK_MNTNS)
1898 return -EINVAL;
1899 } else {
1900 if (mask & FANOTIFY_MOUNT_EVENTS)
1901 return -EINVAL;
1902 if (mark_type == FAN_MARK_MNTNS)
1903 return -EINVAL;
1904 }
1905
1906 /*
1907 * An unprivileged user is not allowed to setup mount nor filesystem
1908 * marks. This also includes setting up such marks by a group that
1909 * was initialized by an unprivileged user.
1910 */
1911 if ((!capable(CAP_SYS_ADMIN) ||
1912 FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV)) &&
1913 mark_type != FAN_MARK_INODE)
1914 return -EPERM;
1915
1916 /*
1917 * Permission events are not allowed for FAN_CLASS_NOTIF.
1918 * Pre-content permission events are not allowed for FAN_CLASS_CONTENT.
1919 */
1920 if (mask & FANOTIFY_PERM_EVENTS &&
1921 group->priority == FSNOTIFY_PRIO_NORMAL)
1922 return -EINVAL;
1923 else if (mask & FANOTIFY_PRE_CONTENT_EVENTS &&
1924 group->priority == FSNOTIFY_PRIO_CONTENT)
1925 return -EINVAL;
1926
1927 if (mask & FAN_FS_ERROR &&
1928 mark_type != FAN_MARK_FILESYSTEM)
1929 return -EINVAL;
1930
1931 /*
1932 * Evictable is only relevant for inode marks, because only inode object
1933 * can be evicted on memory pressure.
1934 */
1935 if (flags & FAN_MARK_EVICTABLE &&
1936 mark_type != FAN_MARK_INODE)
1937 return -EINVAL;
1938
1939 /*
1940 * Events that do not carry enough information to report
1941 * event->fd require a group that supports reporting fid. Those
1942 * events are not supported on a mount mark, because they do not
1943 * carry enough information (i.e. path) to be filtered by mount
1944 * point.
1945 */
1946 fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
1947 if (mask & ~(FANOTIFY_FD_EVENTS|FANOTIFY_MOUNT_EVENTS|FANOTIFY_EVENT_FLAGS) &&
1948 (!fid_mode || mark_type == FAN_MARK_MOUNT))
1949 return -EINVAL;
1950
1951 /*
1952 * FAN_RENAME uses special info type records to report the old and
1953 * new parent+name. Reporting only old and new parent id is less
1954 * useful and was not implemented.
1955 */
1956 if (mask & FAN_RENAME && !(fid_mode & FAN_REPORT_NAME))
1957 return -EINVAL;
1958
1959 /* Pre-content events are not currently generated for directories. */
1960 if (mask & FANOTIFY_PRE_CONTENT_EVENTS && mask & FAN_ONDIR)
1961 return -EINVAL;
1962
1963 if (mark_cmd == FAN_MARK_FLUSH) {
1964 if (mark_type == FAN_MARK_MOUNT)
1965 fsnotify_clear_vfsmount_marks_by_group(group);
1966 else if (mark_type == FAN_MARK_FILESYSTEM)
1967 fsnotify_clear_sb_marks_by_group(group);
1968 else
1969 fsnotify_clear_inode_marks_by_group(group);
1970 return 0;
1971 }
1972
1973 ret = fanotify_find_path(dfd, pathname, &path, flags,
1974 (mask & ALL_FSNOTIFY_EVENTS), obj_type);
1975 if (ret)
1976 return ret;
1977
1978 if (mark_cmd == FAN_MARK_ADD) {
1979 ret = fanotify_events_supported(group, &path, mask, flags);
1980 if (ret)
1981 goto path_put_and_out;
1982 }
1983
1984 if (fid_mode) {
1985 ret = fanotify_test_fsid(path.dentry, flags, &__fsid);
1986 if (ret)
1987 goto path_put_and_out;
1988
1989 ret = fanotify_test_fid(path.dentry, flags);
1990 if (ret)
1991 goto path_put_and_out;
1992
1993 fsid = &__fsid;
1994 }
1995
1996 /* inode held in place by reference to path; group by fget on fd */
1997 if (obj_type == FSNOTIFY_OBJ_TYPE_INODE) {
1998 inode = path.dentry->d_inode;
1999 obj = inode;
2000 } else if (obj_type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
2001 obj = path.mnt;
2002 } else if (obj_type == FSNOTIFY_OBJ_TYPE_SB) {
2003 obj = path.mnt->mnt_sb;
> 2004 } else if (obj_type == FSNOTIFY_OBJ_TYPE_MNTNS) {
2005 obj = mnt_ns_from_dentry(path.dentry);
2006 }
2007
2008 ret = -EINVAL;
2009 if (!obj)
2010 goto path_put_and_out;
2011
2012 /*
2013 * If some other task has this inode open for write we should not add
2014 * an ignore mask, unless that ignore mask is supposed to survive
2015 * modification changes anyway.
2016 */
2017 if (mark_cmd == FAN_MARK_ADD && (flags & FANOTIFY_MARK_IGNORE_BITS) &&
2018 !(flags & FAN_MARK_IGNORED_SURV_MODIFY)) {
2019 ret = !inode ? -EINVAL : -EISDIR;
2020 /* FAN_MARK_IGNORE requires SURV_MODIFY for sb/mount/dir marks */
2021 if (ignore == FAN_MARK_IGNORE &&
2022 (!inode || S_ISDIR(inode->i_mode)))
2023 goto path_put_and_out;
2024
2025 ret = 0;
2026 if (inode && inode_is_open_for_write(inode))
2027 goto path_put_and_out;
2028 }
2029
2030 /* Mask out FAN_EVENT_ON_CHILD flag for sb/mount/non-dir marks */
2031 if (!inode || !S_ISDIR(inode->i_mode)) {
2032 mask &= ~FAN_EVENT_ON_CHILD;
2033 umask = FAN_EVENT_ON_CHILD;
2034 /*
2035 * If group needs to report parent fid, register for getting
2036 * events with parent/name info for non-directory.
2037 */
2038 if ((fid_mode & FAN_REPORT_DIR_FID) &&
2039 (flags & FAN_MARK_ADD) && !ignore)
2040 mask |= FAN_EVENT_ON_CHILD;
2041 }
2042
2043 /* create/update an inode mark */
2044 switch (mark_cmd) {
2045 case FAN_MARK_ADD:
2046 ret = fanotify_add_mark(group, obj, obj_type, mask, flags,
2047 fsid);
2048 break;
2049 case FAN_MARK_REMOVE:
2050 ret = fanotify_remove_mark(group, obj, obj_type, mask, flags,
2051 umask);
2052 break;
2053 default:
2054 ret = -EINVAL;
2055 }
2056
2057 path_put_and_out:
2058 path_put(&path);
2059 return ret;
2060 }
2061
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [brauner-vfs:vfs.all 11/48] fs/notify/fanotify/fanotify_user.c:2004:13: warning: variable 'obj' is used uninitialized whenever 'if' condition is false
2025-02-05 16:16 [brauner-vfs:vfs.all 11/48] fs/notify/fanotify/fanotify_user.c:2004:13: warning: variable 'obj' is used uninitialized whenever 'if' condition is false kernel test robot
@ 2025-02-05 16:20 ` Christian Brauner
0 siblings, 0 replies; 2+ messages in thread
From: Christian Brauner @ 2025-02-05 16:20 UTC (permalink / raw)
To: kernel test robot, Miklos Szeredi; +Cc: llvm, oe-kbuild-all, Christian Brauner
On Thu, Feb 06, 2025 at 12:16:27AM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git vfs.all
> head: b7601b2abc4dbae86d85da3939ce185eac2ed4ff
> commit: 21c1471c81dc7fd8de1f47d74cef9efc91356971 [11/48] fanotify: notify on mount attach and detach
> config: i386-buildonly-randconfig-005-20250205 (https://download.01.org/0day-ci/archive/20250206/202502060049.cygRkOiu-lkp@intel.com/config)
> compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250206/202502060049.cygRkOiu-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202502060049.cygRkOiu-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> >> fs/notify/fanotify/fanotify_user.c:2004:13: warning: variable 'obj' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
> 2004 | } else if (obj_type == FSNOTIFY_OBJ_TYPE_MNTNS) {
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/notify/fanotify/fanotify_user.c:2009:7: note: uninitialized use occurs here
> 2009 | if (!obj)
> | ^~~
> fs/notify/fanotify/fanotify_user.c:2004:9: note: remove the 'if' if its condition is always true
> 2004 | } else if (obj_type == FSNOTIFY_OBJ_TYPE_MNTNS) {
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/notify/fanotify/fanotify_user.c:1819:11: note: initialize the variable 'obj' to silence this warning
> 1819 | void *obj;
> | ^
> | = NULL
> 1 warning generated.
>
>
> vim +2004 fs/notify/fanotify/fanotify_user.c
Folded:
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 1dcab38ca003..f2d840ae4ded 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -1816,7 +1816,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
unsigned int mark_cmd = flags & FANOTIFY_MARK_CMD_BITS;
unsigned int ignore = flags & FANOTIFY_MARK_IGNORE_BITS;
unsigned int obj_type, fid_mode;
- void *obj;
+ void *obj = NULL;
u32 umask = 0;
int ret;
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2025-02-05 16:16 [brauner-vfs:vfs.all 11/48] fs/notify/fanotify/fanotify_user.c:2004:13: warning: variable 'obj' is used uninitialized whenever 'if' condition is false kernel test robot
2025-02-05 16:20 ` Christian Brauner
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