diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 9e483fface1e..32b461c5d04b 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -688,7 +688,7 @@ static __init int fsnotify_init(void) { int ret; - BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 23); + BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 24); ret = init_srcu_struct(&fsnotify_mark_srcu); if (ret) diff --git a/include/linux/fs.h b/include/linux/fs.h index 5f7ac5b548a4..3f4d59464965 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1265,6 +1265,7 @@ extern int send_sigurg(struct file *file); #define SB_I_RETIRED 0x00000800 /* superblock shouldn't be reused */ #define SB_I_NOUMASK 0x00001000 /* VFS does not apply umask */ #define SB_I_NOIDMAP 0x00002000 /* No idmapped mounts on this superblock */ +#define SB_I_ALLOW_HSM 0x00004000 /* Allow HSM events on this superblock */ /* Possible states of 'frozen' field */ enum { diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 8d1849137a96..d91aa064f0e4 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -144,12 +144,29 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, */ lockdep_assert_once(file_write_not_started(file)); - if (!(perm_mask & MAY_READ)) + if (!(perm_mask & (MAY_READ | MAY_WRITE | MAY_ACCESS))) return 0; if (likely(!FMODE_FSNOTIFY_PERM(file->f_mode))) return 0; + /* + * read()/write() and other types of access generate pre-content events. + */ + if (unlikely(FMODE_FSNOTIFY_HSM(file->f_mode))) { + int ret = fsnotify_path(&file->f_path, FS_PRE_ACCESS); + + if (ret) + return ret; + } + + if (!(perm_mask & MAY_READ)) + return 0; + + /* + * read() also generates the legacy FS_ACCESS_PERM event, so content + * scanners can inspect the content filled by pre-content event. + */ return fsnotify_path(&file->f_path, FS_ACCESS_PERM); } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index c38762b62bf1..9bda354b5538 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -57,6 +57,8 @@ #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ /* #define FS_DIR_MODIFY 0x00080000 */ /* Deprecated (reserved) */ +#define FS_PRE_ACCESS 0x00100000 /* Pre-content access hook */ + /* * Set on inode mark that cares about things that happen to its children. * Always set for dnotify and inotify. @@ -78,11 +80,14 @@ */ #define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE | FS_RENAME) +/* Content events can be used to inspect file content */ +#define FSNOTIFY_CONTENT_PERM_EVENTS (FS_OPEN_PERM | FS_OPEN_EXEC_PERM | \ + FS_ACCESS_PERM) /* Pre-content events can be used to fill file content */ -#define FSNOTIFY_PRE_CONTENT_EVENTS 0 +#define FSNOTIFY_PRE_CONTENT_EVENTS (FS_PRE_ACCESS) -#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ - FS_OPEN_EXEC_PERM) +#define ALL_FSNOTIFY_PERM_EVENTS (FSNOTIFY_CONTENT_PERM_EVENTS | \ + FSNOTIFY_PRE_CONTENT_EVENTS) /* * This is a list of all events that may get sent to a parent that is watching diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f5a08f94e094..97a2c04c2b37 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3404,7 +3404,8 @@ static int selinux_path_notify(const struct path *path, u64 mask, perm |= FILE__WATCH_WITH_PERM; /* watches on read-like events need the file:watch_reads permission */ - if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE)) + if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_PRE_ACCESS | + FS_CLOSE_NOWRITE)) perm |= FILE__WATCH_READS; return path_has_perm(current_cred(), path, perm);