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| author | Amir Goldstein <amir73il@gmail.com> | 2022-06-29 17:42:09 +0300 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2022-07-01 14:51:49 +0200 |
| commit | 8afd7215aa97f8868d033f6e1d01a276ab2d29c0 (patch) | |
| tree | 5e5db4b5d657460abb6165b38821d3de13464165 /fs/notify | |
| parent | 31a371e419c885e0f137ce70395356ba8639dc52 (diff) | |
| download | lwn-8afd7215aa97f8868d033f6e1d01a276ab2d29c0.tar.gz lwn-8afd7215aa97f8868d033f6e1d01a276ab2d29c0.zip | |
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>
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index a9eea037fee9..6781d46cd37c 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -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, |