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Subject[PATCH V2] sysfs_notify is only possible on file attributes
Date
If sysfs_notify is called on a binary attribute, bad things can
happen, so prevent it.

Note, no in-kernel usage of this is currently present, but in the
future, it's good to be safe.

Changes in V2:
- Also ignore sysfs_notify on dirs, links
- Use WARN_ON rather than silently failing
- Compiled and tested (huge apologies about first submission)

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
fs/sysfs/file.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 602f56d..d2bb7ed 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -449,10 +449,12 @@ void sysfs_notify_dirent(struct sysfs_dirent *sd)

spin_lock_irqsave(&sysfs_open_dirent_lock, flags);

- od = sd->s_attr.open;
- if (od) {
- atomic_inc(&od->event);
- wake_up_interruptible(&od->poll);
+ if (!WARN_ON(sysfs_type(sd) != SYSFS_KOBJ_ATTR)) {
+ od = sd->s_attr.open;
+ if (od) {
+ atomic_inc(&od->event);
+ wake_up_interruptible(&od->poll);
+ }
}

spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags);
--
1.7.10.4


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