The patch titled
inotify: read return val fix
has been added to the -mm tree. Its filename is
inotify-read-return-val-fix.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
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------------------------------------------------------
Subject: inotify: read return val fix
From: Nick Piggin <npiggin@xxxxxxx>
Fix for inotify read bug (bugzilla.kernel.org #6999)
Problem Description:
When reading from an inotify device with an insufficient sized buffer, read(2)
will return 0 with no errno set. This is because of an logically incorrect
action from the user program thus should return an more logical value. My
suggestion is return -EINVAL as for bind(2).
This patch is based on the proposal from Ryan <wolf0403@xxxxxxxxxxx>, and
feedback from John McCutchan <john@xxxxxxxxxxxxxxxxx>.
Return -EINVAL if we have not passed in enough buffer space to read a single
inotify event, rather than 0 which indicates that there is nothing to read.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Acked-by: "John McCutchan" <john@xxxxxxxxxxxxxxxxx>
Cc: Ryan <wolf0403@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/inotify_user.c | 10 +++++++++-
1 files changed, 9 insertions(+), 1 deletion(-)
diff -puN fs/inotify_user.c~inotify-read-return-val-fix fs/inotify_user.c
--- a/fs/inotify_user.c~inotify-read-return-val-fix
+++ a/fs/inotify_user.c
@@ -455,8 +455,16 @@ static ssize_t inotify_read(struct file
break;
kevent = inotify_dev_get_event(dev);
- if (event_size + kevent->event.len > count)
+ if (event_size + kevent->event.len > count) {
+ if (ret == 0 && count > 0) {
+ /*
+ * could not get a single event because we
+ * didn't have enough buffer space.
+ */
+ ret = -EINVAL;
+ }
break;
+ }
if (copy_to_user(buf, &kevent->event, event_size)) {
ret = -EFAULT;
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
git-block.patch
mm-vm_insert_pfn.patch
mm-vm_insert_pfn-tidy.patch
buffer-memorder-fix.patch
fs-fix-__block_write_full_page-error-case-buffer-submission.patch
inotify-read-return-val-fix.patch
sched-avoid-div-in-rebalance_tick.patch
-
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