5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx> [ Upstream commit 936d6a38be39177495af38497bf8da1c6128fa1b ] Plumb the pieces to add a FID report to error records. Since all error event memory must be pre-allocated, we pre-allocate the maximum file handle size possible, such that it should always fit. For errors that don't expose a file handle, report it with an invalid FID. Internally we use zero-length FILEID_ROOT file handle for passing the information (which we report as zero-length FILEID_INVALID file handle to userspace) so we update the handle reporting code to deal with this case correctly. Link: https://lore.kernel.org/r/20211025192746.66445-27-krisman@xxxxxxxxxxxxx Link: https://lore.kernel.org/r/20211025192746.66445-25-krisman@xxxxxxxxxxxxx Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx> Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> [Folded two patches into 2 to make series bisectable] Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- fs/notify/fanotify/fanotify.c | 11 +++++++++++ fs/notify/fanotify/fanotify.h | 9 +++++++++ fs/notify/fanotify/fanotify_user.c | 8 +++++--- 3 files changed, 25 insertions(+), 3 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 45df610debbe4..465f07e70e6dc 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -609,7 +609,9 @@ static struct fanotify_event *fanotify_alloc_error_event( { struct fs_error_report *report = fsnotify_data_error_report(data, data_type); + struct inode *inode; struct fanotify_error_event *fee; + int fh_len; if (WARN_ON_ONCE(!report)) return NULL; @@ -622,6 +624,15 @@ static struct fanotify_event *fanotify_alloc_error_event( fee->err_count = 1; fee->fsid = *fsid; + inode = report->inode; + fh_len = fanotify_encode_fh_len(inode); + + /* Bad fh_len. Fallback to using an invalid fh. Should never happen. */ + if (!fh_len && inode) + inode = NULL; + + fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0); + *hash ^= fanotify_hash_fsid(fsid); return &fee->fae; diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 80af269eebb89..edd7587adcc59 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -208,6 +208,8 @@ struct fanotify_error_event { u32 err_count; /* Suppressed errors count */ __kernel_fsid_t fsid; /* FSID this error refers to. */ + + FANOTIFY_INLINE_FH(object_fh, MAX_HANDLE_SZ); }; static inline struct fanotify_error_event * @@ -222,6 +224,8 @@ static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event) return &FANOTIFY_FE(event)->fsid; else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME) return &FANOTIFY_NE(event)->fsid; + else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR) + return &FANOTIFY_EE(event)->fsid; else return NULL; } @@ -233,6 +237,8 @@ static inline struct fanotify_fh *fanotify_event_object_fh( return &FANOTIFY_FE(event)->object_fh; else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME) return fanotify_info_file_fh(&FANOTIFY_NE(event)->info); + else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR) + return &FANOTIFY_EE(event)->object_fh; else return NULL; } @@ -266,6 +272,9 @@ static inline int fanotify_event_dir_fh_len(struct fanotify_event *event) static inline bool fanotify_event_has_object_fh(struct fanotify_event *event) { + /* For error events, even zeroed fh are reported. */ + if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR) + return true; return fanotify_event_object_fh_len(event) > 0; } diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index c053038e1cf3c..fa3dac9c59f69 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -339,9 +339,6 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, pr_debug("%s: fh_len=%zu name_len=%zu, info_len=%zu, count=%zu\n", __func__, fh_len, name_len, info_len, count); - if (!fh_len) - return 0; - if (WARN_ON_ONCE(len < sizeof(info) || len > count)) return -EFAULT; @@ -376,6 +373,11 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh, handle.handle_type = fh->type; handle.handle_bytes = fh_len; + + /* Mangle handle_type for bad file_handle */ + if (!fh_len) + handle.handle_type = FILEID_INVALID; + if (copy_to_user(buf, &handle, sizeof(handle))) return -EFAULT; -- 2.43.0
