This is a note to let you know that I've just added the patch titled
fanotify: Report fid info for file related file system errors
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fanotify-report-fid-info-for-file-related-file-syste.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 74eca5c9b4651ee089d144ffd00aa131a9609f8d
Author: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Date: Mon Oct 25 16:27:41 2021 -0300
fanotify: Report fid info for file related file system errors
[ 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>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 34ed30be0e4d4..0d36ac3ed7e99 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -334,9 +334,6 @@ 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;
@@ -371,6 +368,11 @@ 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;
