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Code Issues Releases Wiki Activity

fanotify: cleanups for fanotify_mark() input validations 

Create helper fanotify_may_update_existing_mark() for checking for
conflicts between existing mark flags and fanotify_mark() flags.

Use variable mark_cmd to make the checks for mark command bits
cleaner.

Link: https://lore.kernel.org/r/20220629144210.2983229-3-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Amir Goldstein 2022-06-29 17:42:09 +03:00 committed by Jan Kara
parent 31a371e419
commit 8afd7215aa
2 changed files with 26 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
fs/notify/fanotify/fanotify_user.c
View File

@ -1187,6 +1187,19 @@ static int fanotify_group_init_error_pool(struct fsnotify_group *group)
sizeof(struct fanotify_error_event));
}
static int fanotify_may_update_existing_mark(struct fsnotify_mark *fsn_mark,
unsigned int fan_flags)
{
/*
* Non evictable mark cannot be downgraded to evictable mark.
*/
if (fan_flags & FAN_MARK_EVICTABLE &&
!(fsn_mark->flags & FSNOTIFY_MARK_FLAG_NO_IREF))
return -EEXIST;
return 0;
}
static int fanotify_add_mark(struct fsnotify_group *group,
fsnotify_connp_t *connp, unsigned int obj_type,
__u32 mask, unsigned int fan_flags,
@ -1208,13 +1221,11 @@ static int fanotify_add_mark(struct fsnotify_group *group,
}
/*
* Non evictable mark cannot be downgraded to evictable mark.
* Check if requested mark flags conflict with an existing mark flags.
*/
if (fan_flags & FAN_MARK_EVICTABLE &&
!(fsn_mark->flags & FSNOTIFY_MARK_FLAG_NO_IREF)) {
ret = -EEXIST;
ret = fanotify_may_update_existing_mark(fsn_mark, fan_flags);
if (ret)
goto out;
}
/*
* Error events are pre-allocated per group, only if strictly
@ -1557,6 +1568,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
__kernel_fsid_t __fsid, *fsid = NULL;
u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS;
unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
unsigned int mark_cmd = flags & FANOTIFY_MARK_CMD_BITS;
bool ignore = flags & FAN_MARK_IGNORED_MASK;
unsigned int obj_type, fid_mode;
u32 umask = 0;
@ -1586,7 +1598,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
return -EINVAL;
}
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
switch (mark_cmd) {
case FAN_MARK_ADD:
case FAN_MARK_REMOVE:
if (!mask)
@ -1675,7 +1687,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
if (mask & FAN_RENAME && !(fid_mode & FAN_REPORT_NAME))
goto fput_and_out;
if (flags & FAN_MARK_FLUSH) {
if (mark_cmd == FAN_MARK_FLUSH) {
ret = 0;
if (mark_type == FAN_MARK_MOUNT)
fsnotify_clear_vfsmount_marks_by_group(group);
@ -1691,7 +1703,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
if (ret)
goto fput_and_out;
if (flags & FAN_MARK_ADD) {
if (mark_cmd == FAN_MARK_ADD) {
ret = fanotify_events_supported(group, &path, mask, flags);
if (ret)
goto path_put_and_out;
@ -1729,7 +1741,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
}
/* create/update an inode mark */
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) {
switch (mark_cmd) {
case FAN_MARK_ADD:
if (mark_type == FAN_MARK_MOUNT)
ret = fanotify_add_vfsmount_mark(group, mnt, mask,

9
include/linux/fanotify.h
View File

@ -59,15 +59,16 @@
#define FANOTIFY_MARK_TYPE_BITS (FAN_MARK_INODE | FAN_MARK_MOUNT | \
FAN_MARK_FILESYSTEM)
#define FANOTIFY_MARK_CMD_BITS (FAN_MARK_ADD | FAN_MARK_REMOVE | \
FAN_MARK_FLUSH)
#define FANOTIFY_MARK_FLAGS (FANOTIFY_MARK_TYPE_BITS | \
FAN_MARK_ADD | \
FAN_MARK_REMOVE | \
FANOTIFY_MARK_CMD_BITS | \
FAN_MARK_DONT_FOLLOW | \
FAN_MARK_ONLYDIR | \
FAN_MARK_IGNORED_MASK | \
FAN_MARK_IGNORED_SURV_MODIFY | \
FAN_MARK_EVICTABLE | \
FAN_MARK_FLUSH)
FAN_MARK_EVICTABLE)
/*
* Events that can be reported with data type FSNOTIFY_EVENT_PATH.